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Rosemary & bay on their summer vacation with kumquat

GARDEN FRESH, STILL

Good Only in Theory?

The idea has merit: flowerpots of flavorful herbs decorating windowsills and providing savory additions to meals through the winter. A good part of last season’s garden is packed in the freezer and glistening jars of canned tomatoes line shelves in the basement. The greenhouse is offering a steady supply of lettuce, arugula, and other salad greens.Rosemary against a snowy backdrop

Still, I’m beginning to miss garden-fresh vegetables. Sprinkling some fresh chives on a pan of roasted potatoes might infuse the whole dish with freshness.

The problem is that chives doesn’t thrive on a windowsill, unless the windowsill is very, very sunny. Chives will grow well through the winter with artificial light, but that means a bank of lights permanently poised a few inches above the leaves — so much for the rustic charm of indoor potted herbs. And maybe my taste buds are dulled, but when I snip chives to add to a dish, I take a handful. The plant would need at least a few weeks to recover sufficiently to withstand another harvest.

The same could be said for growing parsley indoors; after each picking, you have to wait too long for another.

I haven’t thrown up my hands at the possibility of growing culinary herbs indoors through the winter. I just have to be very selective in what I grow. Any such herb must pack a lot of flavor into each leaf, survive well indoors, and look pretty. I offer at least two candidates: rosemary and bay laurel. Read more

THE BEST HERB FOR A NORTHERN WINTER

Calamity Avoidance

A horticultural calamity averted. Again. Deb was snipping some leaves from our potted rosemary “tree” for salad dressing and said she noticed that the plant looked a little wilty. I was skeptical. Rosemary leaves are so narrow and stiff that they hardly broadcast their thirst. Still, quite a few rosemary plants have succumbed to winter drought here.Potted rosemary tree in winter

I checked the plant and, in fact, the leaves did look a bit wilty. The probe of my sort-of-accurate electronic moisture tester (which I nonetheless highly recommend) confirmed Deb’s diagnosis. The soil was very dry but, luckily, not to the point of killing the plant.

Allow me to digress . . . Soil scientists represent soil moisture levels with four descriptors. Right after a thorough watering, a soil is “saturated,” with all pores filled with water. Saturation is not desirable in the long term because roots need to “breathe” to do their work of drawing in nutrients and water, which is why plants exhibit the same symptoms from either dry or sodden soil.

Without additional water, gravity begins to pull water down and out of the larger pores of a saturated soil. Once gravity has pulled all the water it can from a soil, the soil is at “field capacity,” much to the pleasure of resident plants. At this point, large pores are filled with air yet some water, which is available for plants, is retained within smaller pores and clinging to soil particles.

Roots continue to slurp more and more water from the soil, but with increasing difficulty because water within even smaller pores and clinging even closer to soil particles is increasingly tightly held there by capillary attraction. Although the soil has moisture, it’s mostly inaccessible to plants. “Wilting point” has been reached.

Eventually, the only moisture left in the soil is that held very tightly in the very smallest pores and pressed tight against soil particles. That’s “permanent wilting point” from which, as the name implies, there’s no turning back. The plant will die.

The actual amount of water in a soil at any of these stages depends on the range of particle sizes in the soil. Clay soils have tiny particles, with tiny spaces between them, so have more water at wilting and permanent wilting point than do sandy soils, with their large particles and large pores.

Soil water vs. particle size

At or near field capacity, sands have more air and less water than clays.

Where were we? Oh, my rosemary plant. I’m figuring it was just teetering on the edge of wilting point. Needless to say, I watered both my rosemary “trees.”

(For a lot more about soil water and how to make the best of it, see my book The Ever Curious Gardener: Using a Little Natural Science for a Much Better Garden.)

Dry Air, Moist (Enough) Soil

You’d think — I once did — that rosemary, because in the wild it billows down dry hillsides overlooking the Mediterranean, would be resistant to drought. It does tolerate dry air. But those wild plants’ roots are in the ground where they can forage far and wide for moisture; not so in a pot.

Also, my rosemary plants are coddled with relatively consistent warmth in winter and a potting mix rich in nutrients. Couple this with low light conditions, even near a south-facing window, and you get very succulent growth. I don’t know what rosemary plants growing on a Grecian hillside are doing now, but my plants are growing like gangbusters. All that succulent growth transpires lots of water, and is very susceptible to drought.

Rosemary, half survived

Left half of this rosemary expired last summer

Once my plants go outdoors in summer, their leaves mature and toughen and growth is less succulent. They do still need sufficient moisture, so I have drip tubes on a timer quenching their thirst (and that of other plants). Except, that is, when the timer’s battery needs replacing and I don’t notice it. That was last summer. The plants were not at the permanent wilting point but a number of branches, which I pruned off, dried up, dead.

In Praise of Potted Rosemary

All this is not to frown upon growing rosemary where it can’t survive winters outdoors. On the contrary, I consider rosemary to be the finest herb for indoor growing. Flavorwise, it packs a powerful punch, unlike chives, for example, a plant that needs to be practically decimated if you really want to flavor something with it. Merely brushing against my rosemary plant releases an aromatic, piney cloud.

Rosemary is also a very attractive houseplant whether grown as a scraggly shrub reminiscent of the wild plants in their native haunts, trained as dense cones, or — as are my plants — as miniature trees. The leaves retain a healthy, verdant look, unlike those of basil, which look sickly and out of their element in dry, relatively dark and cool homes in winter.

Rosemary also rarely suffers from any insect or disease problem.

And finally, properly cared for, rosemary is perennial so can provide aroma, flavor, and beauty   for many, many years.

But you and I do need to pay close attention to watering.

standard bay, rosemary, citrus

Rosemary, with its compatriots, bay and citrus, in summer

Rosemary Tips

Secrets to Survival

I’ve killed plenty of rosemary plants over the years, typically in late winter. At least that’s when I’d discover that they were dead. Casually brushing against the plant would bring dried leaves raining to the floor.
Potted rosemary tree in winter
Problem is that rosemary has naturally stiff leaves. They don’t wilt to broadcast that the plant is thirsty. And then it’s too late; the plant tells you it’s dead as it’s leaves flicker down.

Perhaps like you, I knew that rosemary is native to the Mediterranean region. The picture in my mind is of the plants thriving on a sun-drenched, dry, rocky hillside in poor soil. True enough, except below ground the roots are reaching deep or wide for water. Which my potted plants can’t do.

Following this latter realization — duh! — I haven’t lost a rosemary plant in years. The secret to keeping a potted rosemary plant happy is to keep it well watered, never letting the potting mix dry out. If in doubt, water.

Rosemary roots also need to breathe, and the way that is assured is by adding plenty of perlite to the potting mix. My mix is 1/4 by volume each of perlite, garden soil, compost, and peat moss. The latter two ingredients help retain moisture while, at the same time, provide for aeration.

Making a Rosemary Tree

I mentioned last week that I grow my rosemary plants as miniature trees, a form also known as “standards.” Here’s how I make mine.

(“Standard” does seem like an odd word to describe such a plant until you realize that the “stand” in “standard” does indeed mean just that. “Standard” comes from the Old English words standan, meaning to stand, rather than flop around, and ord, meaning a place. Further muddying the horticultural waters, in fruit growing a “standard” is a full size tree, as opposed to a dwarf tree.)

The easiest way to set a rosemary plant on the road to standard-dom is to begin with a small plant. Rosemary comes in upright or creeping varieties. Upright varieties, such as Majorca Pink and Salem, are naturally inclined to “stand,” but creeping varieties are also easily coaxed in this direction.

Single out a vigorous and upright growing stem as the standard’s future trunk. In the case of a creeping variety, just select any healthy stem and stake it upright to a dowel or thin shoot of bamboo. Shorten all side shoots to direct the plant’s energy into that trunk-to-be.
First 4 steps in training rosemary standard
The goal, in the weeks ahead, is to promote elongation and thickening of the trunk-to-be. To that end, keep cutting away any new stems sprouting from the base of the plant. Keep pinching back to just a few leaves any side shoots. Doing so keeps them subordinate but lets them help thicken the trunk.

Once the trunk reaches full height, goals change: time to stop growth and create a bushy head. But how high is “full height?” It’s all for show, and what looks good depends on how big a head you are going to give the plant and how big a pot the plant will eventually call home. Generally, a head two to three times the height and just slightly more than the width of the pot looks good. Stop growth at the desired height by pinching out the tip of the trunk, a simple operation that awakens growth of buds down along the trunk.
Second four steps in training rosemary tree
Create the bushy head by repeatedly pinching — and thus inducing more branching — all growth that sprouts from the top few inches of the trunk. Now define that head more clearly by completely removing all stems and leaves further down the trunk.

All these prunings need not be wasted, of course. They could be used as flavoring or as cuttings to make yet more plants.

(Creating standards and other methods of pruning all plants is covered in more detail in my book, The Pruning Book, available from the usual sources or, signed by me if you wish, here.)

On Going Rosemary Tree Care

Over time, the bushy head grows larger and larger — too large if left unfettered. So pinch back growing tips regularly, which you’ll probably be doing anyway as you enjoy the rosemary added to tomato sauce or chopped and sprinkled on fish. Unless you’re crazy for rosemary, that amount of pruning won’t be enough to contain the ever expanding head.

And below ground, roots eventually fill their flowerpot. Then they will need more room and access to more nutrients. So once a year, in spring, I tip my plant out of its pot, shear off some roots and soil around the edge of the root ball, then put it back in the pot with new potting mix in the space opened up.
Repotting a standard
Right after I repot the plant, I also give it its annual haircut, shearing the head an inch or so back all over with a pruning or grass shears. Water well and watch the plant fill out with new growth.

All those shearings could, of course, be dried for future use. But why do that? You now have plenty of fresh rosemary, year ‘round. Just don’t neglect watering.
Rosemary standard

The Best Winter Herbs

Mini-Trees for Flavor

Second best to fresh-picked vegetables in winter, which are not within most gardener’s grasp with temperatures in the single digits, are fresh-picked herbs. Fresh-picked herbs — indoors — in winter are within the grasp of most gardeners, even non-gardeners.

Flowering and fruiting demand lots of light energy, but it is the leaves of most herbs that provide us with flavoring, so most herbs do fine in any reasonably bright window. The same goes for normal household temperatures and humidity.

So make space near your windows for herb plants!

Let’s look below ground now. Any potting mix suitable for houseplants will also be to the liking of herb plants. The mix should hold some moisture between waterings while at the same time drain well so that roots, which need to breathe, don’t suffocate. My own mix, made  from equal parts compost, perlite, peat moss, and soil, provides air and moisture as well as nutrients and beneficial microorganisms that keep plants healthy. Soil dug from the garden and used straight up is never suitable; in the confines of a flowerpot, it holds too much moisture.

Now for the plants. Many people, perhaps most, choose basil as their number one herb to grow. Nix on that, indoors. Think of a Mediterranean summer with bright sunlight beaming down on warm soil. That’s what basil needs and what you can’t provide in winter except with supplemental light and, depending on your thermostat setting, supplemental heat. Not in my house.

I’d also suggest against parsley or chives. The problem is that neither grows fast enough to keep up with periodic clipping of the amounts normally harvested.

The best herbs for indoor growing are perennial, woody, subtropical plants. Before you bemoan my nixing of basil, chives, and parsley, consider these perennials: bay, rosemary, sage, and thyme. 

Small, indoor rosemary "tree"

Small, indoor rosemary “tree”

Bay, rosemary, sage, and thyme are also good choices for indoor growing because they do double duty: They’re pretty as well as flavorful, can stand repeated harvest, and live for years and years. My bay tree started life here as a small plant carried back in my backpack from California over 25 years ago. Fresh bay tastes quite different from the dried leaf, and much, much better. My rosemary plants are each a few years old and show no signs of decline.

Both bay and rosemary are happy to be trained as bushes, as topiaries, or as miniature trees. Mine are miniature trees, each plant with a short length of trunk capped by a mop head of leaves (and flowers, now, in the case of rosemary). Their training began early, when I selected a single vigorous shoot for each plant, staked it upright, and removed all other shoots. Once shoots achieved head-height (the height of THEIR proposed head, an artistic rather than horticultural decision), I pinched out their growing tips to induce side shoots to grow. I pinched the tips of side shoots to induce them, in turn, also to branch. All this pinching induced a dense mop head of stems and leaves atop each trunk. Small, lollipop trees.

Maintenance of the bay and rosemary is easy. Both are as large as I’d like them to be so every year or two, they get tipped out of their pots and and inch or two shaved off the outside of their root balls. After returning to their pots, potting soil gets packed into the space beyond the periphery of the root balls, giving new roots access to fresh soil and nutrients.

Their heads also get trimmed periodically to maintain their neat shape. The annual trimming provides a bumper harvest, but a few leaves or stems can be clipped for seasoning any time of year.

Bay laurel tree

Bay laurel

I’m not enough of a fan of sage or thyme to grow them through winter indoors. But sage could be grown as a small, decorative shrub, especially varieties such as Tricolor, with white-edged leaves, Purpurascens, with purplish leaves, or Aurea, with some gold in its leaves. Thyme, which comes in various colors and flavors (lemon or caraway, for example), is a subshrub, or ground cover. How about a thyme ground cover carpeting the ground at the feet of a potted miniature bay tree?

Ongoing care for any of these herbs is watering, which can spell the difference between success or failure. Neither rosemary, bay, sage, nor thyme readily show their thirst with wilting leaves. Years ago, as I brushed past the little rosemary tree I was growing at the time, all the leaves dropped off. The plant was dead.

The potting soil for any of these plants needs to be kept just moist. Scheduled watering won’t do because watering needs changes through the season with growing conditions. A $10 “moisture meter” is an easy way to tell whether a plant is thirsty, as is, with practice, lifting a pot to feel how heavy it is.

Carrying the Sky on Their Backs

I saw two bluebirds a few days ago, but am not ascribing any significance to the sighting. They’re just pretty.

Blueberry Challenge and Aromas Good and Bad

Book Giveaway: AND THE WINNER IS: Andrea Jilling. Andrea, please contact me about mailing out the book. Everyone, stay tuned for more book giveaways in future weeks.
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Blueberry-growing used to be so boring. Each autumn I’d spread soybean meal beneath the plants as fertilizer and top it with 3 inches of leaves, wood shavings, or other mulch. Late each winter I’d prune. In late June, netting would go over the top of the plants and from then on, into September, I’d harvest oodles of blueberries.
Earlier this year I knew things could get interesting. Spotted wing drosophila (SWD), a new pest fond of many fruits, showed up last year in the area and an encore was predicted. And then, starting in early August, my harvested blueberries began to soften quickly and were soon swimming in their own juice. The culprit, SWD, was here, in numbers, with plenty of enticing berries still weighing down the branches.
“Drosophila” might sound familiar from experiments in your high school biology class; it’s a fruit fly. SWD differs from other fruit flies in not waiting for fruit to be ripe or overrripe. This impatient bugger lays eggs in unripe fruit.
Blueberry harvest is an almost daily affair and my blueberries are organic, sustainable, green, artisanal, (very) local, etc., etc., so I couldn’t just start spraying any old pesticide. Fortunately, there is one pesticide, called Entrust (derived from a bacterium collected from the soil of an abandoned sugar mill in the Virgin Isles), that is “organic” and effective against SWD. I did spray and now, despite the mildness of this material, we have to wait 3 days for the spray to dissipate before harvesting berries. Restraint is needed with Entrust because one generation to the next for SWD can take less than 2 weeks, leaving ample opportunity for resistant strains to evolve, especially if the pest overwinters locally (which is not known at this time).
After two sprays of Entrust one week apart, I should and will try something else, in this case a 1% oil spray — also “organic” and relatively benign. In laboratory settings, at least, oil has been effective.
What about all the berries on the plant with SWD eggs in them that are and will hatch into adults? Harvesting them and whisking them into a refrigerator at 34° for 72 hours will kill eggs and larvae. Same goes, of course for freezing them. Another option is to immerse them in that 1% oil mix for 5 to 10 minutes.
The battle against SWD should not — does not — end there. Fine netting encasing the plants could keep flies at bay, as long as it’s put on before SWD arrives or, if resident ones exist, after an early spray of Entrust. Thorough cleanup of infested fruits will keep populations down. We’re throwing soft fruits into a bag which goes into the freezer, and then it’s a dish of fresh frozen eggs and larvae and blueberries for my chickens. Mmmmm.
You might detect some flippancy in my attitude towards this serious pest. That’s because we already have 69 quarts of sound blueberries in the freezer.
(Thanks to Peter Jentsch and Cornell’s Hudson Valley information for much of this information.) 

        UPDATE: Two sprays of Entrust and one spray of horticultural oil, each spray a week apart, seem to have brought SWD under control. Once the berry harvest is over, we’ll let our free-range chickens access into the “Blueberry Temple” too clean up fallen fruit and resident SWD larvae.
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Garlic has been harvested and, as usual, my yields and bulb sizes are nothing to brag about. “You should have cut off the scapes,” suggested more than one person, the scapes referring to the curly, bulbil-topped stalks that emerge from the centers of hardneck garlic plants.
I’m skeptical about scape removal. After all, that greenery does photosynthesize and, hence, help nourish the plant. And while seed development can drain a plant of energy, a scape is capped by small bulbils, not seeds.
A little research yielded widespread recommendations for scape removal, but hard data backing up that

recommendation was generally lacking. What I did learn was: 1) benefits of scape removal depend on the soil and variety of garlic; 2) benefits are greatest in poor soils; 3) benefits may be in terms of yield or bulb size. The most consistent reason to remove the scapes is that they are edible if harvested when just developing.

I don’t like the taste of the scapes so won’t bother removing them. I’m also not a big fan of garlic flavor so tend to plant them outside the garden in out-of-the-way locations where they’re never watered and the soil is not particularly rich. Hence, my poor showing of garlic.
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The garlic is now curing as it hangs from the rafters of my front porch where it, fortunately, keeps its aroma to itself. Along the path leading up to the porch are a few plants whose aromas are a lot more welcome on the way to the front door. Those plants have clustered there not by some grand plan of mine, but just by chance.
Let’s see, first on the way to the door is Jasmine ‘Maid of Orleans’ (Jasminum sambac) whose flowers emit a pure, sweet aroma. The plant has been blooming more or less all summer but you do need to put your nose right up to the flower to smell it. Next comes jimson weed (Datura spp.) and angel’s trumpets

(Brugmansia spp.), both vespertine plants with 6-inch long, trumpet-shaped blossoms that appear sporadically. I’m always enjoying rose geranium, mint, and rosemary, next in line, because its their leaves that are aromatic; a pinch can send me to olfactory heaven anytime I wish, day or night.

Nestled in among these last-named plants is one small pot of alyssum. Alyssum blooms nonstop through summer and into autumn so the honeyed scent can be enjoyed whenever I pass, as long as I stick my nose down into the flowers.