The recent chilly spell has had the pleasant side effect of prolonging spring bloom. Plant development is still ahead of normal, and many plants are in bloom at the same time, providing an interesting display of color in the landscape, as the weekly UMass landscape letter (http://umassgreeninfo.org/landscape_message/lm_welcome.html) points out. Locally however, dry conditions due to lack of rain may be causing abbreviated bloom on some ornamentals. Mulching can help with this, but not too deep and kept away from stems and trunks.
The threat from winter moth and fall cankerworm inchworms has subsided considerably but they are still in evidence. Owners of blueberry bushes may want to apply Bt (Bacillus thuringiensis) sprays mixed with a spreader/sticker, on a weekly schedule. The fungal disease, Azalea leaf gall, (Exobasidium vaccinii) is developing. The usual advice for control is to cut the galls away before they turn white, and destroy them. Exbury azaleas here at home exhibit the galls. Destroying them for years has not changed anything; it must be a stress symptom.
Advice for going organic
It is time for my annual plug for “Teaming with Microbes.” In gardening, it is always time to think about composting. But compost is a mystifying process for many gardeners. Compost, compost tea, compost pile building, using it: am I doing it right? Advice and help exist in a number of sources, but for those who crave authorative information, Jeff Lowenfels’ and Wayne Lewis’ “Teaming with Microbes: a Gardener’s Guide to the Soil Food Web” (Timber Press, Portland OR 2006, 4th printing 2008, 196 ppg.) should be on your bookshelf.
The book details what takes place in soil systems and how, as gardeners and landscapers, we can work with that knowledge to the best advantage of each type of growth. Lawn, ornamentals, vegetables, and trees each have a differing ideal balance of soil organisms: the arthropods, fungi, and bacteria that enable living plants to grow.
While “Teaming with Microbes” could be called a compost geek’s bible, it actually offers a nut-and-bolts approach to transitioning from chemical to organic management, especially for lawns. Not only do the authors lead us step-by-step through good practices and schedules for going organic, whether in the fostering of lawn, ornamentals, vegetables, or woodland, but also the soil science of each system is explained. The book is well illustrated with scores of color photos, diagrams and charts.
COMSOG, the community solar greenhouse in Oak Bluffs, is open for business and has its crops of vegetable plants, including a wide array of heritage tomatoes and more, available for sale. Polly Hill Arboretum conducts its Spring Plant sale on May 29, where choice plants of particular interest are offered to Island gardeners.
In the Garden
We are always advised to make successional plantings of crops, and now is the time to lay those plans. The challenge to accomplish is eating the beets, lettuce, or beans as they come on, but also to have the next crop ready to harvest by the time the first are gone. Some vegetables can be planted and enjoyed fresh for the entire season — pole beans come immediately to mind — while rows of bush beans can be viewed as production crops for the freezer, which are then pulled to make room for nitrogen-loving kale or radicchio, say, for fall. Plant heading broccoli varieties for processing, and sprouting broccoli for season-long floret production for stir fries or steaming.
Barring meteorological catastrophe, by the time you read this it should be safe to plant out tender crops. Some suggestions for timely tasks in the garden might be: Keep onions and garlic well-watered and weeded, to prevent harmful competition. Onions need to make their growth before the summer solstice, at which time they commence to bulb. The cabbage white butterfly is active, so begin a weekly Bt spray schedule on the brassicas: arugula, broccoli, cauliflower, cabbage, kale, and such. Bt is effective on lepidopteran caterpillars only. Various other unknown chewers are active too; neem oil spray would be my first choice of controls to try.
Before setting out tender plants, dig a hole and fill it with a shovelful of compost. It does not need to be ‘finished compost’ for this. Side-dress the rows you already have planted with a good low number organic fertilizer/soil food.
Roses are showing evidence of sawfly larvae, a worm- or slug-like creature that is not controlled by Bt. Skeletonized or scraped–looking leaves are the telltale sign. Early roses are in bloom, as are irises. Tie in wandering canes of climbing roses and clematis. Pinch phlox, Montauk daisies and other chrysanthemum family members. Deadhead lilac bushes. Identify the oldest trunks and renew the plant by cutting a few of them out.
Our gardens appear to be subjected to increasingly violent winds. All the gardeners I talk to comment on this. The need to stake, the great disadvantage of older, tall peony varieties such as “Festiva Maxima,” will soon be required for them and other taller growing perennials. Be ready with a store of stakes and twine. Many newer peonies are as much as a foot shorter, at 24 to 28 inches, a bonus for the busy gardener.
An alternative to staking is the construction of rabbit wire circles, or cages, that are held down by three or four earth staples to both support and also to protect the plant inside from rabbits. I think rusty — that would be vintage — rabbit wire is preferable as it is almost invisible.
On a visit to Longwood Gardens in April, I was impressed by the meticulous staking in the display gardens. Each ramrod-straight foxglove was unobtrusively tied along its stake with old-fashioned green garden string (not twine), and each stake was topped with a small rubber tip.