Are you like me, longing to get out into the garden again? Especially on the warm, spring-like days we’ve been having, it is hard to resist. But it is only March 1, and we need to be careful about what we do in the garden this early. It is too soon to dig, and we should avoid walking on the soil. Since the temperatures have been above freezing, the soil is soft and wet and susceptible to compaction. But there are a few tasks we can accomplish now.

First, if we haven’t done it already, we can take down the holiday décor. Then cut a few branches to force for a harbinger of spring: forsythia, cherry, quince and pussy willows can be cut and put in water to bloom indoors. Bringing forsythia inside is like capturing sunshine.

Next we can tackle some late winter pruning. This is a fine time to attend to late blooming shrubs before they put out their new growth. We can thin suckering shrubs like lilac (Syringa species) and Winterberry (Ilex verticillata), cleaning out suckers and removing some of the oldest wood back to the ground. This allows light into the plant and encourages vigorous blooming on the newer branches. Along the way we can saw off the oldest stems of the Elderberry (Sambucus). The mild weather has brought leaf buds already, so the future shoots we are boosting by removing the old are already visible. A swelling bud is still a thrilling sight—especially this early in the year.

Smokebush (Cotinus coggygria) is another shrub that can be cut back now. To keep it compact and to enhance the leaves’ color, we can go back as far as two or three buds from the base.

Late winter is also the time to consider renovating our native Mountain Laurels (Kalmia latifolia). Their natural habit is loose and airy. We should take a good look to decide what works best in our landscapes. If all we want to do is tame them slightly, encouraging more compact, dense growth, we can prune conservatively right after they bloom in June.

Another approach is to highlight the mountain laurel’s architecture by allowing it to remain tall and spare, revealing its wonderfully craggy trunks and weathered, finely shredding bark. This is almost an Asian, sculptural look. (A fringe benefit of this taller form is that the foliage grows above the level of deer browsing. Though all parts of the plant are poisonous, deer are known to feed lightly on Kalmias when their options are few.)

If, however, our mountain laurels have become scraggly or were damaged by last fall’s storms, we can take advantage of a special feature of this shrub. Kalmias have a swollen collar at the base of the trunk, a burl, which allows for drastic renovation. The burl enables even mature mountain laurels to generate new growth from their woody stems. Now is the time, before they put out any new growth, to prune them back to a few inches above the ground, even down to the burl itself. Numerous new stems will emerge to create a fresh, compact shrub in several seasons. Unfortunately, there will be no blossoms this year.*

Finally, once there is new growth on Butterfly bushes (Buddleia) and  Blur Mist Spirea (Caryopteris), they can be pruned back to about 18 inches from the ground. These will recover quickly and bloom this summer.
-----------------------------------------------
*The mountain laurel’s craggy branches can be saved for building charming arbors, fences, gates and trellises.

Tags: Bllue Mist Spirea, Caryopteris, Buddleia, Butterfly bush, burl, Kalmia latifolia, Mountain Laurel, Cotinus Coggygria, Smokebush, Ilex verticillata, Winterberry, Syringa, Lilac, forsythia, winter pruning Read More

I’m late in extolling the impressive show our native Mountain Laurels put on this year! Roadsides and uncultivated woods appeared to be covered in snow with the heavy white bloom they produced this past month. In 16 years I have never seen such a spectacular season for Kalmia latifolia.

Now that the blossoms have faded, it's time to dead-head (remove spent flowers) to encourage another year of profuse bloom. Plants thoroughly covered with blossoms will produce very little new growth otherwise. If, like some gardeners, you notice a pattern of heavy bloom on alternate years, this could be the reason.  To deadhead Laurels (this applies to Rhododendrons, too), grasp the stem beneath the terminal leaves with one hand. With the other, pinch the base of the spent flower between thumb and forefinger and bend to the side. If it does not snap off neatly, a bend to the opposite side should do it. If, occasionally, the terminal leaves break off with it, I call it pruning. All these dead blossoms make a great addition to the compost.

If we want to garden organically, it only makes sense to go native. Using plants that thrive naturally in our area gives us a head start on a happy, healthy garden without undue effort or resorting to chemicals. Where better to start than with the Mountain Laurel, which is widespread along the Eastern Seaboard, is the state flower for both Connecticut and Pennsylvania and is rated one of the 75 great plants for American gardens by the American Horticultural Society?

In the wild, these evergreen shrubs form thickets along the edges of rocky and sandy woodlands, or where there is an opening in the canopy that creates dappled shade. They provide year-round havens for wildlife, while the bark and foliage offer four-season beauty. Left uncultivated, native Kalmia have an open, airy habit, developing only one or two tall, leggy branches that can eventually reach as high as 20 feet. The cultivars sold in nurseries have been raised with multiple stems for a lush, compact form.  And their blossoms range from white to pinks and red, from solid to patterned, from cup-shaped to stars.

Mountain Laurel like acidic soil with a pH about 5.5. I always thought my naturally acidic soil was fine for them until I tested it and found a pH of 6.5. The laurels on my property, though native, perked up after the addition of an acidifier. (Try aluminum sulfate, ferrous sulfate, or pelletized sulfur.) They don’t, however, like too much fertilizer or wet feet. Once established, they will tolerate drought. Heat and humidity can lead to fungal leaf spot, so pruning for good air circulation will help.

A bonus for gardeners, Mountain Laurels actually like the difficult North side of a house, which protects them from the harshest sun and worst temperature swings. Planting on slopes is fine, too. These natural understory shrubs help prevent water runoff and soil erosion. What they won’t like is being too close to the foundation, where Calcium leaching from cement can raise the pH, or next to roads that get salted in winter. Mulch with leaf mold or compost.

The Kalmia cultivars require only occasional, conservative pruning—cutting just above a crotch—to promote full, balanced bushes. Pruning the natives is another story, one we will tell in late winter when the time is right.

To find a wonderful selection of Mountain Laurel, the place to go is Broken Arrow Nursery in Hamden, CT. Owned by Dr. Richard Jaynes, the pre-eminent breeder of Kalmia latifolia cultivars, this nursery boasts the largest collection in the world. It’s a great source for other native shrubs and perennials, too. Learn more at www.brokenarrownursery.com. Also worth a visit is Highstead Arboretum in Redding, CT, where a large collection of Kalmia cultivars can be viewed in a breathtaking setting. See www.highsteadarboretum.org.

Tags: American Horticultural Society, acidic soil, pH, organic gardening, dead-heading, Highstead Arboretum, Broken Arrow Nursery, Mountain Laurel, Kalmia latifolia, native shrubs, Spring, 75 great plants for American gardens Read More