OF MAPLES AND REDS

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Where’d the Red Go?

Sugar maples (Acer saccharum) are now doing just what I expected of them. But not exactly what I want them to do. Here in New York’s mid-Hudson Valley, at least, this autumn’s leaf show is not quite up to snuff. And it’s also later than in the past. It used to peak here in the middle of October; nowadays, with climate change, the peak has been pushed forward to about now.Autmn view of the 'Gunks mountains

Back to the color: This year the local sugar maples are mostly only yellow, lacking the oranges and the reds that, along with some yellow, really ramp up the blaze of landscapes and forests. Let’s blame that more subdued show on the weather. To know why, let’s backtrack to summer when, quoting from a section in my recent book The Ever Curious Gardener, Using a Little Natural Science for a Much Better Garden:

Green is from chlorophyll, most welcome in spring and through summer, but not what interests me in fall. Chlorophyll must be continually synthesized for a leaf to stay green. The shorter days and lowering sun of waning summer are what trigger leaves to stop producing it, unmasking other pigments lurking there.

Leaves’ yellow and orange colors are aways present, thanks to carotenoid pigments, which help chlorophyll do its job of harvesting sunlight to convert into plant energy. I offer thanks to carotenoids for the warm, yellow glow they give to gingko, aspen, hickory, and birch leaves.

Sugar maple

Sugar maple (not this year)

Tannins are another pigment, actually metabolic wastes, that, all summer, are hidden by chlorophyll. Their contribution to the fall palette are the season’s subdued browns, notable in some oaks and enriching the yellow of beeches.

Because leaves harbor carotenoids and tannins all summer long, nothing particular about autumn weather should either intensify or subdue their autumn show. The only glitch could be an early, hard freeze that occurs while leaves are still chock full of chlorophyll. In that case, cell workings come abruptly to a halt and all we’re left with is frozen, green leaves that eventually drop without any fanfare.

Autumn color also spills out reds and purples, most evident in red maples and some sugar maples, scarlet oak, sourwood, blueberry, and winged euonymous. Those reds and purples come from yet another pigment, anthocyanins. Except for trees like ‘Purple Fountain’ beech and ‘Royal Purple’ smokebush, whose leaves unfold dusky red right from the get go in spring, and remain so all season long, in most leaves anthocyanins do not begin to develop until autumn.Japanese maple

Anthocyanin formation requires sugars so anything that I or the weather does to promote sugar accumulation in autumn will increase anthocyanin levels in leaves. The weather’s role is to offer warm, sunny days to maximize photosynthesis, and cool, but not frigid, nights to minimize nighttime burning up of accumulated sugars. A cloudy, rainy autumn means less red because less anthocyanin is formed, and any that does form is diluted.

As I write this, it’s cloudy and rainy, as it has been so many days this autumn.

Other Reds

I was recently visiting my daughter in Pennsylvania. As we looked around her neighborhood I admired the rich, red, autumn color of the trees lining the streets. Red?! How can that be? What about what I wrote about this autumn’s weather and anthocyanin and red leaves in autumn?

Ah, but science takes care of that, too. Those trees in the Pennsylvania landscape weren’t sugar maples; they were a variety of Freeman maple (Acer × freemanii). Freeman maples are natural and deliberate hybrids of silver maples (Acer saccharinum) and red maples (Acer rubrum), the silver maple contributing fast growth to the hybrids and the red maples contributing strong branches and red leaf color in autumn. Freeman maple

Trees vary, both as to species and locations, in the amounts of pigments found at various times in their leaves. Red maples, as the name implies, have significant amounts of anthocyanins. In these trees, this anthocyanin is present not only in autumn as the chlorophyll fades, but throughout the growing season. Depending on the amount and kind of anthocyanin, its redness would be more or less masked by chlorophyll during the growing season. Some varieties of red maple, and many varieties of Japanese maple, are red or purplish all summer long.

The million dollar question is why a tree would have anthocyanin in its leaves all season long. Various theories have been floated. Anthocyanins do offer protection against excess sunlight, which is why young leaves emerge reddish on some plants.

Seedling red maples

Seedling red maples

(This characteristic does not correlate with the degree of red in leaves in autumn.) It’s also possible that anthocyanins could ward off pests.

Whatever the reason, red or orange or yellow leaves, I’m not complaining. Autumn is still a beautiful season here in the Hudson Valley. 

 

SENSUAL THINGS, AND WATER

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Heady Nights

It’s difficult to work outside in the garden these days, especially in early evening. No, not because of the heat. Not because of mosquitos either. The difficulty comes from the intoxicating aroma that wafts into the air each evening from the row of lilies just outside the east side of my vegetable garden.
cat and lilies
These aren’t daylilies, which are mildly and pleasantly fragrant. Wild, orange daylilies are common along roadways and yellow and hybrid daylilies, often yellow, are common in mall parking lots. (That’s not at all a dis’; the plants are tough and beautiful, and I’ve planted them also.) They’re also not tiger lilies, which lack aroma and sport downward turned, dark red speckled orange flowers with recurved petals. 

My fragrant lilies are so-called oriental hybrid lilies, which are notable for their large flowers and strong fragrance. My favorite among those I grow is Casa Blanca. The flowers are large and lily white (what’d you expect?) except for the threadlike, pale green stamens emerging from their centers, with dark red anthers capping their ends.

Casa Blanca would be worth growing just for the look of the flowers; the fragrance, very sweet and very heady make this bulb a must-grow. Not for everyone, though. A few people dislike this fragrance. For some people it’s more than just stinkiness, the aroma causing nausea, dizziness, or congestion.
Casablanca lily in the garden
Casa Blanca’s stems can rise to about four feet tall, their upper portions circled with almost a dozen of those large blossoms in various stages of ripening. Some years, staked, persimmon orange, Sungold tomatoes grow in that bed, and the tomato and lily plants looked very pretty mingling together. (Tomatoes were, after all, once grown as ornamentals.) 

This year I’m growing kale in that bed which, besides good eating, provides a frilly base from which the lily stems rise.

In Good Taste

Turning to another of the senses . . . taste. Blueberries. They are among my most successful fruits and, as usual, the plants’ stems are bowing to the ground under a heavy load of berries this time of year.
Blueberries galore
Not to brag, but the average yield of a blueberry bush is 3 to 5 quarts. My blueberry bible, Blueberry Culture (1966), states that “proper cultural practices can increase the yield to as much as 25 pints per bush.” I average about 18 pints per bush, with some bushes yielding as much as 24 pints. Organically grown, of course.

I credit my good yield to periodic additions of sulfur to maintain acidity of pH 4.0-5.5, timely watering with drip irrigation especially the plants’ first few years, topping up of existing wood chip, wood shavings, or leafy mulch each fall with an additional 3 inch depth of any organic, weed-free mulch, and pruning every spring. 
Bunch of blueberries
In year’s passed, I also added soybean meal for extra nitrogen to fuel stem growth. Blueberry flower buds develop along growing stems, with flowers open along those stems the following spring. More stem growth means more blueberries, to a point. For many years I have foregone soybean meal because the the plants were overly vigorous, creating a dense jungle that makes getting to the berries too difficult.

One other key to success and topnotch flavor is a net during the summer to fend off birds and — for best flavor — careful picking of only dead ripe fruits.

Water, Too Much or Too Little

So far, the growing season here in the Northeast has been one with both dry spells and wet spells, more than usual of each. Some recent thunderstorms fool many a gardener into thinking that the soil has been thoroughly wetted. But such rains are often only a drop in the bucket.

The only way to know for sure if enough rain has fallen for plants to really slurp up water is to check the soil or measure the actual amount of rainfall. A friend tells me he waters his plants every day. Every day! How much? It could be too much or too little, and probably is one or the other. I like to quantitate things so I measure rainfall or watering, as well as soil moisture, in a few different ways.

First, measuring water added to the soil: The ideal is about a 1 inch depth of water per week, which is equivalent to about a half a gallon per square foot of surface area. For hand watering a young tree, with an estimated root spread of only a couple of square feet, I fill the watering can with a gallon of water and sprinkle it on.
Rain gauge
Rainfall, or the water from a sprinkler, could be measured with a straight-sided container. I use a rain gauge whose tapered body can break down the measurement into tenths of an inch, readable from indoors.

Digital moisture probe.

Digital moisture probe.

I usually measure the actual moisture in the soil with a handy little meter attached to a probe that slides a half a foot down into the soil. As expected, the meter told me today that the soil is very wet. Not surprising after 3 inches of rainfall, as measure in the rain gauge, two nights ago. 

(There’s more about blueberries and water in my books Grow Fruit Naturally and The Ever Curious Gardener.)

Free webinar today, WEEDLESS GARDENING

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“WEEDLESS GARDENING” webinar

Are you interested in having a weedless garden this season? Yes? Learn how at my upcoming WEEDLESS GARDENING webinar. The system I’ll describe does more that just deal with weeds. It also lets your garden use water more efficiently, conserves valuable soil organic matter, lets you plant earlier in spring, and does not disrupt beneficial fungi and other friendly soil organisms. Starting a new garden? Here’s the fastest way to get the soil prepared and plants growing.

I’ll cover all this, and more, in the WEEDLESS GARDENING webinar. The webinar is free, at 2 pm EST on Sunday, June 6, 2021.

This webinar is sponsored by Inniswood Garden Society. To register for this program, please visit: www.bit.ly/AnnualMtgRegister

PLANT SALE NOW LIVE

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Lee Reich’s 13TH (?) ANNUAL PLANT SALE
(of mostly lesser grown but delectable fruits)

Because of covid, the sale is now online, with scheduled pickups here at the farmden in New Paltz, NY.

Note that there are limited quantities of al plants, each available to the first taker. So order soon.

To see plant list, order, pay, and — VERY IMPORTANT — schedule a pickup time (May 29-31 and June 2), go to https://leesannualplantsale.squarespace.com

CALLING ALL VOLUNTEERS

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A Returning Beauty

I have some of the nicest volunteers in my garden. Some of them have been people, many of them are plants, and one of my favorites – among the plants, that is – is columbine. Years ago, I planted some native columbines, those dainty plants whose orange and yellow flowers hover on thin stalks above their ferny foliage. Since being planted, these wildings self-seed – volunteer, that is — every year in various nooks and crannies around my yard, such as in the thin crevice of soil between my bluestone front path and the adjacent stone wall.
       Native columbine
I once also planted cultivated columbines, the common McKana Giants, and their offspring have been volunteering around the yard as well. Flowers and foliage of these more cultivated sorts are similar to the natives, just bigger in all respects, which is not necessarily better. Or worse. Just different.
Cultivated columbine
Colors of these larger columbines are different from that of the natives. My original McKana Giants sported various colored bracts and petals. Seedlings of these plants, 20 years later, have segregated out into just a few solid colors, and the cool thing is that each year’s colors are a bit different from the previous years’.

Columbine and trumpet honeysuckle

The once “high-bred” columbines back by my vegetable garden have mostly soft pinks flowers, a color that marries well with the scarlet of the trumpet honeysuckles behind them.
Right near my front door, poking through cracks between the bluestone patio and my home’s brick wall, is a big, beautiful columbine with dusky, purple flowers.

I do help out these volunteers by weeding out those in excess or interloping where they shouldn’t.
volunteer columbine

Greenhouse Volunteers

Not all my volunteers are beauties. Some are only practical.

For instance, in the greenhouse, I once planted claytonia, also known as miner’s lettuce. It’s one of many lesser known “greens” that thrive in cool weather so are good for adding variety to salads once fresh cucumbers and tomatoes are just a memory.

Since that first planting, late every fall claytonia shows up all over the place in the greenhouse with no help from me. “All over the place” usually applies to a weed, but when I grab a whorl of claytonia leaves and lift gently, the plant gives in and lifts, hardly disturbing the soil.
Claytonia in greenhouse
This past winter was relatively mild and, for the first time, I see a few claytonia plants out in the garden. Uh-oh.
Claytonia in garden
Years ago, I would sow celery seeds in flats in February for transplanting in May; the seeds take a long time to sprout and then the seedlings grow very slowly. No more. I once grew celery for winter in the greenhouse and, in spring, when seed stalks started pushing up from the plants’ middles, I decided to let the plants do their thing. They self-seeded, so all I need to do these days is weed out excess. Some of those excess can also be potted up for transplanting into the garden.

Some greenhouse volunteers — mâche and cilantro — help out both in the greenhouse and in the garden. That’s nice of them because then I get the early crop in the greenhouse and the later crop outdoors.

Mâche show up in winter in the greenhouse, again in early spring and then again in late summer. The early spring crop is from plants that overwintered; mâche, though delicate in texture and flavor, is perhaps the most cold-hardy and among my favorite of all fresh salad greens. In spring, plants go to seed and the seeds slumber in the ground until cool weather coaxes them to sprout.

Mache

Mache

Cilantro, in contrast, only sprouts in late winter in the greenhouse and mid-spring out in the garden. It does so profusely. Like claytonia it never segues over into the category of “weed” because any excess is easily removed.

Sacrilege and Hope

One volunteer that shows up only outside, in the garden, is garlic. This may sound like sacrilege, but I don’t grow garlic. Many years ago I did, and then decided to devote the garden space to vegetables whose garden-fresh flavor is truly better than anything I could buy. And anyway, I don’t use that much garlic. So I stopped planting it.

Garlic did not go away, though. It’s been propagating by the little offsets it produces atop its flower stalk to the point where it’s everywhere among the leaf-mulched berry plants adjacent to my garden. (It’s not allowed in my garden.) The mostly grassy plants hardly ever yield bulbs worth saving but the tender, grassy stalks are useful. If I call this a weed in my garden, the parts of my garden where I grow it are indeed very weedy.
Naturalized garlic
At the other extreme is one volunteer that once liked it here, but evidently no longer does. That’s dill, which used to self-seed in just the right amount, and usually would confine itself to the same corner of my vegetable garden.

A couple of years ago, only one or two plants showed up, and last year none. I’m not sure why. I want it to come back so I bought some seeds for this year. I’m hoping it comes back as a volunteer again in future years.

MY MENAGERIE EXPANDS (and a free webinar)

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A Little Bit of the Mediterranean

The UPS guy arrived yesterday with a long, narrow cardboard box containing the latest addition to my menagerie, a menagerie of mostly Mediterranean plants. “Mostly” because not all of them have roots in the Mediterranean. But all of them thrive and are grown in Mediterranean climates of mild winters and sunny summers.

My collection is a “menagerie” because, although all the plants thrive and are grown in Mediterranean climates, the makeup is quite diverse. There’s the evergreen pineapple guava (Acca sellowiana that also goes under the common name feijoa), olive, rosemary, bay laurel, and Meyer lemon.

Pollinating pineapple guava

Pollinating pineapple guava

And a few of the plants — black mulberry (Morus nigra), Pakistani mulberry (Morus macroura), pomegranate, and fig — go dormant and lose their leaves in winter.

Pakistan mulberry fruit

Pakistan mulberry fruit

Here at the farmden, winter temperatures can plummet to minus 20°F, so getting these plants to thrive involves more than just giving them a nice, sunny spot in the ground outdoors. Except for the figs, some of which are in the ground in the greenhouse, all the others grow in pots. Every couple of years or more, depending on the plant, I slide a potted plant out of its pot, shave off some of its roots, and then put it back into its pot with some new potting soil. Stems likewise need pruning to keep a plant from growing too big and, in the case of fruiting plants, to keep the plant fruitful.

Root pruning and repotting

Root pruning and repotting

Potted plants spend summers basking in sunlight, just as they would in a Mediterranean climate. Come winter, they’re protected from frigid weather but kept cool, ideally 25 to 45°F. The winter home for the deciduous plants is in the dark of either in my walk-in cooler or my cold basement. Evergreen plants need light year ‘round, which they get in various south-facing, sunny windows in cool rooms. More light allows for warmer winters indoors.

If all this sounds like a lot of trouble, it is. So why do it? I like the way the plants look but, even more so, I like the way the plants taste, especially those that bear fruit. Thus far, my most successful Mediterranean fruit has been fig; black mulberry and Meyer lemon have borne pretty well; my harvest from pineapple guava and olive have been only a few fruits each year. Still nothing from the pomegranate.

Another -Quat besides Kumquat and Sunquat

The newest addition to my menagerie is loquat (Eriobotrya japonica), bearer of plum-size yellow or orange fruits. I’ve only tasted two loquats in my life, both from fruit stands at a market (Paris and Jerusalem); neither was anything to write home about. But I know from experience the superiority of home-grown fruits. And descriptions I’ve read that loquat’s flavor combines that of apricot and peach, or that of peach, citrus, and mango. would alone would warrant my giving this plant a
try. 
LoquatI’m also attracted to loquat for its several unique features. It’s a distant relative of apple, pear, and plum, yet it flowers in autumn and the fruits ripen in spring or early summer. The leaves, large, leathery, and dark green are ornamental enough for some gardeners in equable climates to grow this plant strictly as an ornamental. Loquat leafAn attractive potted plant would do well to boost the eye appeal of my ragged collection of potted plants hugging sunny windows in winter.

Loquat’s small, white flowers emit a sweet and heady aroma — another plus — and are borne in clusters at the branch tips. Good to know when it comes to pruning: if I shorten too many branches, I’ll have to say good-bye to flowers.

As an evergreen, this plant will join other Mediterranean evergreens in winter at a sunny window in a cool room. Light through even a sunny window pales compared to outdoor sunlight at the same time of year. One source says that loquat tolerates a bit of shade. That’s hopeful.

From China, Around the World, and Now Here

Loquat’s botanical roots are in China. From there, it travelled to Japan where it evidently was a hit. The Japanese have been enjoying the fruits for about 1,000 years. Now the plant is widespread in climates where it can be grown. Because the plant is a little finicky about fruiting, with 26° killing the flowers, 24° causing developing fruits to drop, 19° killing unopened flower buds, and the whole plant dying at 12°. Add to that the plants’ not liking too much summer heat or wind. No wonder commercial production of this fruit is limited.

Looking at my loquat’s leaves, I feel almost like I’m looking at an old friend, or at least a close relative of an old friend. Yes! The plant reminds me of medlar (Mespilus germanica), a cold-hardy uncommon fruit that I’ve grown and enjoyed for many years (described in my books Landscaping with Fruit and Grow Fruit Naturally, and also in my, for now. out of print Uncommon Fruits for Every Garden). Besides similar leaves, both fruit at the tips of new stems growing off one-year-old wood.

Medlar

Medlar

The fruit has even been called “Japanese medlar,” and the Spanish word nispero can mean either medlar or loquat. At one time, loquat was placed in the genus Mespilus, along with medlar.

My loquat, the variety Golden Nugget, does not need a pollinator and is allegedly “juicy, firm, meaty, and sweet.” And grafted trees (mine is) bear within 2 or 3 years. So I’m hopeful. If my Golden Nugget loquat is really flavorful it will earn a place, along with four in-ground figs, in the greenhouse, where the climate is truly Mediterranean.

FREE WEBINAR ON PRUNING FRUIT TREES, SHRUBS, AND VINES!

I’ll be giving this free webinar on Saturday, April 24, 2021 from 9-10:30AM EST. Register for it at https://www.eventbrite.com/e/pruning-fruit-trees-shrubs-and-vines-tickets-149851978301

SWEET POSSIBILITIES

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It’s time to prune, and to help you, I’ll be holding a PRUNING WEBINAR on March 29, 7-8:30 EST. Learn the tools of the trade, how plants respond to pruning, details for pruning various plants, and enjoy a fun finale on an easy espalier. There’ll be time for questions also. Cost is $35 and you can register with Paypal or credit card here.

Choice Syrups

I’ve given up on maple syrup this year. The tree I tapped was too small to yield anything significant. 

I’d almost given up on river birch syrup. I thought perhaps it was the timing — and, have since learned, that it is! Sap from any one of a number of birch species doesn’t begin to flow until temperatures are consistently 50°F or higher, which arrives near the end of the maple tapping season and continues until about the time the trees leaf out.

River birch, tapped

River birch, tapped

Black walnut was another possibility for tapping. I previously had pooh-poohed it because, much as I love this tree’s nuts, I imagined the aroma of the leaves or the hulls oozing its way into the sap. Ugh!

Another reader reported that walnut syrup is delicious and I should try it, so I did. Sap started dripping as soon as I drilled the holes. The first batch is boiled down, and it is delicious. Not that different from maple syrup, with just a slightly different, smoother flavor. Nothing reminiscent of the nuts, leaves, or husks, though.

Black walnut tree, tapped

Black walnut tree, tapped

Processing was via the same low-tech approach I’ve used for maple syrup, merely adding each day’s “catch” to a big stock pot sitting on the wood stove. The woodstove is stoked pretty much continuously this time of year, so the sap is always evaporating, with the added bonus of humidifying the house.

I see a few eyebrows going up. Sticky walls and ceiling are what comes to some minds upon the mention of cooking down maple sap indoors. Well, that’s usually myth. Sticky walls and ceiling only result when the sap is in an active boil and bubbles bursting on the surface of the liquid send little droplets of sugar water into the air and onto walls and ceilings.

Until the final stage of my sap-making, the sap is just slowly evaporating. The vapor given off by slowly evaporating, simmering, or boiling a solution of any sugar and water is nothing more than water vapor. That’s why the maple (or black walnut) sugars become concentrated in the remaining liquid. They stay in the pot.

In those final stages of concentration, with much reduced liquid volume, the liquid can indeed reach an active boil. The pot of liquid announces that it’s nearing that stage by starting to gurgle like a baby, at which point it needs to be watched closely, mostly so that the syrup doesn’t get too concentrated or burn. The finish point is when the temperature of the liquid reaches about 219 degrees F. 
Boiling sap
I discovered a big difference from maple syruping when I attempted to strain off schmutz in the boiled down black walnut sap. The schmutz was a jelly that quickly clogged up the strainer. The amount of schmutz can vary from tree to tree, with time of year, and who knows what else. Turns out that black walnut sap is high in pectin, aka schmutz. Perhaps calling it “black walnut jelly” would make it more appetizing. Black walnut syrup

Too Late to Prune, Say the Squirrels?

Someone wrote me that squirrels were chewing on a Norway maple last week and the sap was seen dripping down, then went on to ask if that meant it was too late to prune. Perhaps the squirrels were enjoying some of the sweet sap.

Yes, you can tap and boil into syrup the sap of all kinds of maples; I’ve tapped and made syrup from silver maple, red maple, boxelder, and, of course, sugar maple. And each tastes slightly different from the other.

Getting back the pruning… It’s not at all too late. It’s fine to “dormant” prune any plants up until the time when they unfurl their leaves in spring. Actually, peach trees are best pruned when they are blooming.

Another good question might be: Why not just cut the Norway maple down to the ground? The trees are invasive and displacing our sugar maples, they have poor fall color, and they create lugubrious shade beneath which grass and much else can’t grow. Mostly, people keep these trees because they are already in place and full grown.

FEARLESS PRUNING

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FEARLESS PRUNING WORKSHOP/WEBINAR

A workshop/webinar to take the mystery out of pruning, so that lilac and rose bushes, apple trees,  blueberry shrubs — all trees and shrubs, in fact — can be pruned to look their best and be in vibrant health. Fearlessly.

Asian pear espalier floweringTopics will include:
•Why prune?
•Tools for pruning.
•How plants respond to various kinds and timing of pruning.
•Details for pruning flowering shrubs, trees, evergreens, and fruit plants.
•And a fun finale on creating an easy fruiting espalier. (Don’t know what espalier is? You’ll learn it at the webinar.)

And, of course, there will be time for your questions.

Date: March 29, 2021 
Time: 7-8:30 pm EST
Cost: $35

Registration Link
https://us02web.zoom.us/webinar/register/WN_RfkO-_nJT8S-LximcfG24Q

After registering, you will receive a confirmation email containing information about joining the webinar.

HOW ABOUT THOSE OLD SEED PACKETS?

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It’s wasted effort to sprinkle dead seeds into furrows either in the garden or seed flats. Seeds are living, albeit dormant, embryonic plants which do not live forever.
Sprouting bean seeds
When you buy a packet of seeds, you’re assured of their viability. Government standards set the minimum percentage of seeds that must germinate for each type of seed. The packing date and the germination percentage often are stamped on the packet. (The germination percentage must be indicated only if it is below standard.) I write the year on any seed packets on which the date is not stamped.

Your old, dog-eared seed packets may or may not be worth using this season. It depends on where the packets were kept and the types of seeds they contain. Last year I got tired of trying to decide how well my seeds were stored and which were still worth sowing; I took action.

Anti-Aging Treatments

Conditions that slow biological and chemical reactions also slow aging of seeds, i.e. low temperature, low humidity, and low oxygen. In years past, I’ve stored seeds in canning jars in my freezer, then moved the jars to the refrigerator as the freezer filled in fall. Powdered milk sprinkled into the bottom of the jars maintained low humidity. (Or so I assumed.) But all those jars took up lots of space, especially as my seed collections grew, and seed packets don’t pack well into canning jars.

As far as low oxygen storage, it’s not practical for most of us. I did try, one year, to create low oxygen seed storage by reversing gaskets and putting a one way valve on a bicycle pump. Bicycle vacuum pumpThis allowed me to draw some of the air out of the jars with a tube connecting the pump to a ‘FoodSaver Wide-Mouth Jar Sealer.’ It did (usually) create somewhat of a vacuum but it was too much trouble to get at the seeds and re-seal a jar each time. And, again, seed packets don’t pack well into canning jars.

So last year I came up with a figurative “better mousetrap.” After much searching for a plastic, freezer-safe, air-tight, leak-proof, reasonably-sized tub for the bulk of my seeds — a stout order, all this — I came upon the ‘Komax Biokips 35-Cup Large Food Storage Container.’ Perfect!

I measured, cut, and hot-glued a piece of 1/4-inch plywood to run up the center of the tub to allow for two rows of seed packet. A couple of 100 gram silica gel packets in the tub at the end of each row keeps humidity low. The packets are easily rejuvenated in a warm oven for 20 minutes. I just measured the humidity in the tub (I like to measure); it’s a dry 17%.
Seed storage, in tub
Moving the tub into the relative coolness of my basement in summer should maintain conditions in line with the guideline for seed storage that Fahrenheit temperature plus relative humidity should total less than 100. Come cooler weather in fall and then cold weather in winter, back the the tub goes to a shelf in my unheated workshop.

Worth Saving?

Seeds differ in how long they remain viable. Even with the best storage conditions, it’s not worth the risk to sow parsnip or salsify seeds after they are more than one year old. Two years of sowings can be expected from packets of carrot, onion, and sweet corn seed; three years from peas and beans, peppers, radishes, and beets; and four or five years from cabbage, broccoli, brussels sprouts, cucumbers, melons, and lettuce.

Among flower seeds, the shortest-lived are delphiniums, aster, candytuft, and phlox. Packets of alyssum, Shasta daisy, calendula, sweet peas, poppies, and marigold can be re-used for five or ten years before their seeds get too old.

In a frugal mood, I might do a germination test to definitively measure whether an old seed packet is worth saving. Counting out at least 20 seeds from each packet to be tested, I spread the seeds between two moist paper towels on a plate. Inverting another plate over the first plate seals in moisture and then the whole setup goes where the temperature is warm, around 75 degrees. After one to two weeks, I peel apart the paper towels and count the number of seeds with little white root “tails”.
Seed germination test
I figure the percentage, and if it’s low, the seed packet gets tossed into the compost pile (not given away!). Or, I might use the seed and adjust my sowing rate accordingly. 

And the Record Is . . .

Among the shortest-lived seeds are those of alpine plants; their viability might plummet after only a couple of weeks. 

As far as longest-lived seeds, there’s the story of the 10,000 year old lupine seed that germinated after being taken out of a lemming burrow in the Yukon permafrost. Alas, it’s only a story, one debunked by radiocarbon dating.

The true record for seed longevity was, until recently, 2,000 years, and was held by a date palm grown from seed recovered from an ancient fortress in Israel.

No one knows exactly what happens within a seed to make it lose its viability. Besides lack of germination, old seeds undergo a slight change of color, lose their lustre, and show decreased resistance to fungal infections. There’s more leakage of substances from dead seeds than from young, fresh seeds, so perhaps aging influences the integrity of the cell membranes.  Or, since old seeds are less metabolically active than young seeds, the old seeds leak metabolites that they cannot use.

(The above was adapted from my book The Ever Curious Gardener: Using a Little Natural Science for a Much Better Garden available from the usual sources and, signed, from me.)