Archive | October 2016

More trouble for our trees?

by Mary Learman, OCMGA Master Gardener

Did you lose trees to Dutch Elm Disease? How about the Emerald Ash Borer? What we don’t need is another disease that wipes out our trees — especially in the Urban Forest where a very high percentage of the trees planted in most cities may be some form of Maple.

wpr-meiller-weather-plantdiseases-tarspotIf you noticed black spots on the leaves of your Maple this year, you’re not alone. Fortunately, although the black spots are unsightly, they’re probably not a harbinger of yet another disaster-in-the-making for our tree population. However, it is something you should address!

For more information about caring for your Maples, follow this link and read the article by Jill Nadeau of Wisconsin Public Radio.

 

Plant now for a long Tulip season

Tulip lovers stretch the season by planting lots of different species and cultivars. Though each only blooms for a short time, the tulip parade can last two full months if you plan it carefully.

Tulipa fosteriana 'Purissima'

Tulipa fosteriana ‘Purissima’

Early: The first tulips are low to the ground, including the wide-leafed Kaufmannianas, sometimes called water-lily tulips because of the shape of the flowers, and Gregii’s, known for their mottled leaves. Soon after them come Emperor, aka Fosteriana, tulips, the earliest of the long-stemmed types; Single Early, which is usually slightly taller than Emporor; and Double Early, ditto.

Mid Season: Once the days lengthen and weather warms up, you’ll get Triumphs, first of the truly long-stemmed florist’s types, which come in a wider range of colors than the early birds. Also Peony-flowered tulips, known for their lush doubleness; and Giant Darwin, the florist’s tulip on steroids.

Viridiflora tulipan (Viridiflora tulip)

Viridiflora tulipan (Viridiflora tulip)

Late: This is the season for Darwin tulips, also known as Single Late, the classic tall-stemmed cups of color that first come to mind when you hear the word tulip. It’s also the time for exotica: huge Parrot tulips, with their twisted and ruffled petals; urn-shaped Lily-flowered tulips; Viridifloras, with flames of green rising up the outside of the brightly colored flowers; and Fringed tulips, sometimes listed as Tulipa crispa, their petal edges frilled with narrow teeth that glow when the light shines through.

Species: There are dozens of species tulips available, primarily through mail order. Smaller and more delicate than garden tulips, they are mostly mid-season bloomers, with a few earlies, such as the tiny white T. biflora, and a few members of the late show, such as the bright red T. wilsoniana (T. montana). The available array keeps growing, so it is best to buy from a purveyor who is clear about blooming time in the catalog.

Shearing is not Pruning

This time of year, we’re preparing for winter and many folks are doing some Fall pruning. Do you say you’re grabbing your shears

Ficus benjamina (formally sheared)

Ficus benjamina (formally sheared)

or your pruners? There is a difference between pruning and shearing.

Pruning means cutting off a part of a living plant, and covers everything from snipping a twig to reaching deep inside a tree canopy and sawing off a major branch. Shearing is a particular kind of pruning, one in which only branch tips are cut, and they are cut as a group rather than individually.

The goal of shearing is to force lots of small outer branches while creating a smooth outline. The result — if it is successful — is that the sheared plant loses it’s natural identity and becomes a formal shape.

Creating a box hedge topiary by hand

Creating a box hedge topiary by hand

The most common example of the technique is the flat-faced wall of a sheared hedge, but people also shear plants into mounds, pyramids, graduated balls on sticks, or (in a few extreme cases) things like chess pieces and leaping dogs.

Shearing at the simple hedge level seems as thought it should be easy; just hold the shears at the proper angle and clip away. In fact, it takes patience, practice — and strong arms — to see where you need to cut and then do the cutting properly.

Electric hedge trimmers promise to relieve you of much of the work, and they do make it go faster. But they are heavier than hand shears, their speed increases the chance of mistakes, and they have a regrettable tendency to tear everything they touch instead of cutting cleanly.

Kalanchoe can rebloom!

kalanchoe-blossfeldianaThe ubiquitous Kalanchoe (pronounced kal-an-KO-ee) is at almost every grocery store that has a floral department, and getting one as part of a get-well or birthday celebration is as common as getting a card! However, the plants are always blooming beautifully upon receipt, but when the blooms begin to fade the plant tends to look straggly and is often discarded.  Not necessary! There is nothing quite like coming in from a bitter winter’s day and seeing the mass of bright red flowers. Even the variations on red that are available — the softer apricot, deeper magenta, or singular yellow — brighten both the room and your soul. Compact, bushy, and about a foot tall, kalanchoe is common in winter, but once the flowers disappear, many people abandon them. That’s a shame, because with very little effort, they can be forced to bloom whenever you want.

Kalanchoe is what is known as a short-day plant, but it is really the length of the night that matters. For kalanchoe to set flower buds, it needs six to eight weeks of days with 14 to 16 hours of uninterrupted darkness. And uninterrupted means exactly that, so you’ll have to put it in the closet every afternoon — over in the corner where your poinsettia spends the fall, as it needs the same treatment. Pick the right closet because anything in it you might need won’t be available until morning. About a month after the dark period ends, color should be showing as the buds begin to break.

Other than that, kalanchoe is a cinch to grow when given lots of sun (except when it’s in the closet). It thrives in warmth, 65ºF or more, although it tolerates temperatures just above freezing. It should have the chance to go a bit dry between waterings, and it likes a general fertilizer every two or three weeks when new leaves are growing.

When it gets too big it can be cut back pretty hard, leaving only three leaves on each branch. If you do cut it back, wait until it has at least three pairs of new leaves on each branch (about two to three months) before tossing it back in the closet to initiate flowering.

Keep your Kale thru Winter

Once the days are short and cold, you can’t expect kale to keep growing. But you can help it survive almost indefinitely. The trick, which also works for Swiss chard and other hardy greens, is to keep the soil around the roots from freezing.

Start by applying a thick blanket of organic mulch — straw or shredded leaves. That will be enough if you are in zone 7 or the warmer parts of zone 6. If it’s colder, use bales of straw and old windows (or clear plastic) to build a lean-to cold frame.

Place a row of bales close to the long side of the kale row. They should be to the north if the row runs east-west, to the east if it runs north-south. Put another row on top so you have a wall about 3 feet high. On each short side, make a sloping wall by butting single bales firmly against the back wall, then topping them with partial bales.

Now use the windows (or clear plastic sheeting) to cover the front, making sure the cover does not touch the plants. At the top, windows can just lean against the straw. Plastic should be draped and held in place on top of the bales by rocks or a heavy board. At the bottom, where the cover touches the ground, mound on a few inches of soil to hold it and seal out drafts.

At this point, you should have a structure whose sloping, clear roof faces south or west. Use loose straw to fill in any gaps in the walls. That’s it. Throw a heavy blanket over the cover when night temperatures are predicted to fall below 20ºF; and open the frame at the top on warm, sunny days or you’ll cook your kale before you bring it indoors. Don’t try this with root crops; mice and voles will colonize the bales of straw if you feed them beets and carrots!