Dry, Wet, Bad, Good?

Some Bad

Wow! What a gardening year this has been. Looking back on 2018, it’s been the oddest year ever in terms of weather, insects, and disease.

After starting off the season parched, seemingly ready to go into drought, the weather in July did an about face. The rains began. Average precipitation here in the Northeast is about 4 inches per month. July ended up with about 6 inches, August saw 5 inches, September 8 inches(!), October 5 inches, and November 8 inches(!!).

All that rainfall brought humidity, which might have been responsible for my celeriac plants hardly growing, then rotting.

Celeriac in new home

Celeriac, early in the growing season, before the rains

(Perhaps not, because this was my third growing season of failure with celeriac.) I’m taking this as a celeriac challenge. Perhaps next year I’ll try them in a large tub where I can have more control over soil composition and moisture.

The humidity also had too many figs morph into fuzzy, gray balls as they softened and sweetened.

Tomatoes this year tasted very good, as usual, but yield was way down and too many showed some rotting areas. (In my experience, growing tomatoes under variable soil and weather at various locations around the country, their flavor is mostly a matter of genetics; a good variety tastes good everywhere.) Particularly irking was anthracnose disease, which often isn’t noticeable when fruits are harvested, but quickly shows up as round, sunken areas.

Onions suffered this season. Mostly they were stunted, and I’m not sure why.

Zucchini was a bust because the plants petered out from powdery mildew and vine borers just after midsummer. I usually circumvent these common problems with multiple plantings, starting new zucchini plants in early summer to replace the decrepit ones. I forgot to replant this summer (probably because I don’t like zucchini all that much anyway).

Medlar is an uncommon, very old-fashioned fruit that I’ve grown for many years. Although it’s gotten a bad rap for it’s ugly — to some people — appearance, the flavor is delicious, the soft flesh creamy smooth like apple butter with a similar flavor livened with vinous overtones. Medlar fruit in handUsually the plant is pest-free but a few years ago something, perhaps a fungus, perhaps an insect, started attacking it, leaving the flesh dry and crumbly. I have yet to identify the culprit so that appropriate action can be taken.Medlar pest damage

Some Good

Not that this past growing season was bad. I won the battle against soft scale insects (mealybugs) on my greenhouse figs, although their ecological niche was filled by just-as-bad armored scale insects. A close eye and an occasional spray of Neem oil kept flea beetles at bay from eggplants.

A couple of the same Neem sprays beginning in mid-September may have kept a new pest in the area, Allium leafminer (ALM, Phytomyza gymnostoma) at bay. Last year each of my near perfect-looking leeks revealed a rotted stalk as I lifted them out of the ground.

Allium leafminer

Allium leafminer

Then again, I did plant this past season’s leeks far from where the previous season’s leeks grew. Then again, the ALM flies can fly. Then again, maybe they weren’t here this year; perhaps the weather was not to their liking.

Nice leeks

This past season’s leeks

There was also no sign this past season of the white flies that decimated my kale the previous season.

Spotted wing drosophila (SWD), a species of fruit fly that has invaded the country relatively recently, did mostly ruin autumn ripening yellow and black raspberries. But little damage was suffered by my favorite (and perennially most successful) fruit, blueberries, probably thanks to some experimental traps developed by Peter Jentsch of Cornell University.

SWD trap

SWD trap

Peppers were even more of a success than usual, mostly due to my staking the plants. The only fault of Sweet Italia, my favorite variety for its early ripening, for its flavor, and for its good yields, is that the fruit-laden plants flop over under their own weight. Eventually, the small bamboo stakes I used proved only partially adequate; next year they’ll get the stakes they deserve.

I treated a few beds in spring to a relatively new method for weed control: tarping. Laying a sunlight-blocking tarp down on the ground for a couple of weeks or more in spring warms the soil beneath, stimulating germination of any weed seeds lurking there. The sprouting seeds are disappointed by the incessant darkness. They die. Timing, temperature, sunlight, and duration of tarping all play a role in this techniques effectiveness.

(Tarping is very different from using black plastic mulches. The latter are kept in place all season long, with garden plants growing in holes or slits in the plastic. Soil beneath the plastic can suffer from lack of air or, if not drip irrigated, lack of water. Also, the tarp — mine came from www.billboardtarps.com — can be folded up and re-used for many seasons.)

And finally, we were happy to find some assassin bugs and anchor stink bugs, Stiretrus anchorago, in the garden. Both are beneficial insects — yes even that particular stink bug.

Immature beneficial stink bug

Immature beneficial stink bug

Good Overall

All in all, it was a good season — as always. The secret is to grow many different kinds of plants. No season, no matter what the weather or pests, has ever been bad for all plants.

 

Mystery Solved, and Frigid Dealings

Mystery Plant: No longer a Mystery

Last week I mentioned my brother’s mystery shrub, which he wanted to prune back heavily. I told him it was okay to do so even though I — and a number of experts I consulted — could not identify the plant.

(Drum roll . . .) The plant has finally been identified, by Mark Brand of the University of Connecticut, as Wilson rhododendron, Rhododendron x laetevirens. I had narrowed it down to R. carolinianum, which is one of the parents of this hybrid, the other being R. ferrigineum.

Wilson rhododendron flower bud

Wilson rhododendron flower bud

My brother’s not noticing flowers on this rhododendron is understandable. It’s a super cold hardy but sparse bloomer that’s grown mostly for its foliage; the pointy leaves don’t droop or curl, but remain perky, even in frigid weather.

Now I can sleep nights.

It was Cold Outside!

Talk about frigid weather: I was surprised at how cold it was on the farmden during my Thanksgiving visit to my bro’ in Rhode Island. The night of Friday, November 23rd, New Paltz weather reported a low of 7° F. Brrrrr. As I’ve mentioned before, I live in a valley. Cold air, which is heavier than warm air, sinks into low spots, bringing the temperature right out in my garden even lower, down to 3° F.

(I knew this even when in Rhode Island, thanks to Sensorpush, a nifty device that transmits minute by minute temperature and humidity conditions to my cell phone from wherever the device is located.)

It’s all about microclimates, which are localized differences from the general climate due to such influences as heat-absorbing masonry walls and paths, which keep temperatures warmer in winter. Or nearby bodies of water, which keep temperatures warmer in winter and cooler in summer. Or differences in elevation, lowering the temperature 6°F for every 1000 feet of elevation, and low lying areas.

Lower temperatures with elevation might seem contradictory to the locally colder temperatures in my garden that night. These colder temperatures occur only when still windless air and a clear sky let any heat the ground has accumulated by day re-radiate back to the heavens. A cloudy night or tree cover would reflect that re-radiated heat back downwards, preventing the cooling. With radiative cooling, air near the ground is coldest, and and warmer air hovers higher up.

Microclimate Adjustment=Fresh Salad Greens

As a gardener, I can play around with microclimate and have it work for me, as evidenced from the fresh endive, winter radishes, lettuce, and turnips just harvested from right out in the garden.

Preparation for that harvest began in late summer with spreading compost in the bed and the sowing of endive seeds. I planted turnip, lettuce, and winter radish seeds in the bed in September.

Back in early October I spaced metal hoops 4 feet apart along the bed, each one spanning from one side to the other of the bed. Later on in October, I covered the hoops with a length of clear plastic, slitted row cover creating a tunnel over the bed. The slits keep the interior of this mini-greenhouse from overheating.Tunnel, clear plastic, vented, closeup

Moving into November, temperatures gradually cooled but still not enough to threaten the covered plants. Between the plants natural cold hardiness and the cover, I figured they were fine into the low 20s. (For more on microclimates and their manipulation, see my new book The Ever Curious Gardener.)

Short days and low hanging sun, coupled with cool temperatures, were not providing conditions for plant growth. But the plants were, by then, fully grown, so no more growth was needed. At that point I laid a cloth cover over the tunnel to keep out further depths of cold. Light became immaterial; I just wanted the plants alive and fresh.Tunnel with covers, Dec, endive revealed

And so they have remained, even after temperatures plummeted to 3°.

Not only are the plants alive and fresh. Cold temperatures have brought out the best in their flavor. The veggies are crisp, sweet, and tangy.Turnip from tunnel

Read the Book, Bro’

To Prune or Not To Prune, That is the . . .

So I visited my brother and his family for Thanksgiving. As usual, we walked around his yard to look at his plantings. As usual, he asked my advice, this time about pruning. (As usual, he didn’t want to consult a copy of my book, The Pruning Book, which I had given him a few years ago. “Why read it, when I can just ask you?!” he says.)My brother's mystery shrub

He was considering taking blades to a row of handsome, evergreen shrubs along the front of his house. Over the years, the lengthening branches had sprawled out to encroach upon the bordering lawn, in some places leaving exposed bare stems. He questioned whether new growth would sprout if he lopped all those sprawling stems back to near the roots.Close up of mystery shrub stems

But what was the plant? I had an excuse, admittedly rather lame, for not knowing it: I learned all my ornamentals in Wisconsin where not many broadleaf evergreens are hardy. No matter. Sometimes you can figure out how to prune an unknown plant by just studying its growth habit.

Many evergreens, including most pines, Douglas firs, rosemary, and some rhododendrons, will not sprout new growth if cut back to bare old wood. (At the other extreme are boxwoods and yews, which sprout all over the place no matter how they are cut back.)

I suggested going ahead with drastic pruning of the unknown shrub. My confidence came from seeing many young sprouts emerging from the old stems right near where they emerged from the ground and then bent over from their own weight. Hormones within plants promote sprouting of vigorous, new shoots near the high point of a stem wherever it bends over. Pruning a stem back likewise promotes sprouting right near the cut.

I Pass Judgement

Looking across the front path, bro’ next asked me how I liked the pruning job he’d done on his rhododendrons. Hmmm, pretty good.My brother's pruned rhododendron

As often happens with rhododendrons, they are planted near a home and then too often grow so large as to swallow up windows, even the whole side of the home. His had done so, and he had pruned stems back to the height he wanted.

Two problems with this pruning. First, as noted above, when a stem is pruned back, most regrowth, and the most vigorous regrowth, occurs just below the cut. So although he cut the plant down to size, he should expect it to start growing back up to its previous size quickly.

The other problem with this pruning is that it leaves the plant looking butchered, large wounds gaping out atop thick stems whose upward mobility has been abruptly stopped. The best pruning jobs are ones where a plant looks nice without looking as if it has even been pruned.

My approach would have been to make a few cuts of the largest stems down in the interior of the shrub, where the stems originated. The largest stems would also be the tallest ones, so such cuts would be effective in lowering the plant. If too many need removal at once, the operation could be spread over 2 or 3 years. Then the pruning cuts would hardly be noticed, and letting light down low among the stems would promote healthy new growth starting low.

With all that said, my brother’s rhodies didn’t look too bad — and he has the opportunity over the next year or two to make my suggested cuts. Lucky for him, his rhodie was not one of the few that are reluctant to make new sprouts in lopped back older wood.

Moving On

Once I get started pruning, it’s sometimes hard to stop. As I looked at his yew shrubs along another part of his house, I suggested paring down the size of that rectangular block of greenery.My brother's yew hedge

Pruning yew is easy. Since it resprouts up and down stems no matter how severely it’s cut, you can do almost anything to it. His large hedge could even be cut down to stumps to begin life anew — quickly, because it has an established root system.

Most important when reducing the size of the hedge, no matter how it’s cut, is to reduce the whole hedge to a size smaller than finally desired. When maintenance trimming a shrub with hedge shears, trimming is generally further out from where the newest shoots began their growth for the season. That’s why hedges grow larger over time, unless they’re periodically lopped back more drastically, which doesn’t leave them looking that good until those cuts are covered by new growth.

And the Mystery Shrub is  . . . ?

I don’t feel so at a loss at not being able to identify my brother’s mystery shrub: I sent a photo of it to a few experts, none of whom could identify it.

GREAT GIFT IDEAS

Gardening books, of course.
The Pruning BookThe Ever Curious Gardener

 

 

 

 

Uncommon Fruits for Every Garden

 

Landscaping With FruitGrow Fruit Naturally

Of Crocs and Glads

No-Dig Crocs

Plants grow and multiply, which sometimes causes trouble. Such trouble was highlighted this week as I was digging up my crocosmia bulbs.

Crocosmia up closeBackpedaling perhaps 20 years, you would have found me ordering crocosmia bulbs from a mail-order catalog. I’d seen the plants blooming in a friend’s garden in New Jersey and marveled at the graceful flower stems that arched up and out from clumps of sword-shaped leaves. Lined up near the ends of each flower stalk were pairs of tubular, hot scarlet blossoms.

Crocosmia isn’t supposed to be cold-hardy outdoors where winter temperatures drop below minus 10 degrees F. (hardiness zone 5), so the first couple of autumns, as instructed, I dug up the bulbs for winter storage. Each spring following, the plants would get off to a slow start, finally blooming late in the season or not at all.

In disappointment or laziness, I stopped digging the bulbs up each fall. I was surprised to see them appear in spring anyway. Not only did they appear in spring; they had some real oomph, growing almost as luxuriantly as the ones in my friend’s garden. To make matters better, they started blooming earlier, in July, and in great profusion, and they have done so reliably year after year with no help at all from me.Crocosmia and daphne

The crocosmias also multiplied, and they did so with such enthusiasm that there became just too many of them at the original location. So I started digging. And I uncovered bulb after bulb after bulb, ready to bloom and multiply next year. Now I have to decide what to do with all those bulbs. Plant them? Give them away? Compost them? I would have never thought I could have had too many crocosmias.

Glads Won’t Die

Does anybody around here still dig up their gladiolas each fall? I don’t, but to no avail. Left outside, they still survive every winter. Yuk. (Gladiolus “bulbs” are, like crocosmia “bulbs,” actually bulb like structured called “corms.”)

I don’t like gladiolas. Perhaps it’s because they are the most popular flower for funerals.

At any rate, I did, for some reason, plant some glads over 30 years go, glads whose beautiful salmon, pink color I subsequently felt was wasted on glad flowers. The nice color couldn’t outweigh the funereal associations, so after a couple of years of digging them up for storage each fall, I decided to sacrifice them to winter cold.Gladiolus

Unfortunately, they reappeared each year, and have continued to do so annually. I have to chuckle whenever I read instructions such as: “Corms should be dug after foliage has matured and started turning brown. Lift corms carefully with a spade or spading fork, taking care not to cut into the corm. Cut the tops off 1inch above the corm and dry for 2 to 4 weeks in a warm location (70-80 degrees Fahrenheit) with good air circulation. Remove the old corm which is beneath the new corm. Discard any rotted or damaged corms. Cut stems back to within an eighth of an inch of the corm. Place the corms in an onion sack or old nylon panty hose. Hang from a wall or ceiling. Ideal storage temperatures are between 35 and 40 degrees Fahrenheit.”

Hah! Doing nothing at all has, unfortunately, worked fine for me. At least the gladiolas haven’t multiplied as fast as the crocosmias.

Cold Air, Not So Cold Soil

The whole concept of winter hardiness for a plant only whose roots (or corms, in the case of crocosmia and gladiola) need to survive winter is hazy. After all, three feet down in the soil almost everywhere, temperatures hover around 50 degrees Fahrenheit.

Lay some mulch on top of any soil and penetration of winter cold can’t reach as deeply as through bare soil or lawn. Bare soil doesn’t peek out anywhere in my garden. Whatever is not lawn has been mulched year after year for many years with leaves, wood chips, sawdust, compost, hay, or whatever other organic materials I can get my hands on. (No, my garden isn’t three feet higher than it was when I started because those organic mulches decompose, enriching the soil as they do so.)

Nonetheless, the ground that the crocosmias and glads call home is well-insulated from winter cold. Warmer winters for the past few years have also helped these “nonhardy” bulbs survive outdoors, especially the less cold-hardy gladiolus.