Summer settles in for Martha’s Vineyard gardeners

Bittersweet berries add variety to floral arrangements, but the plant has fewer beneficial motives in the wild. — Photo by Susan Safford

Vegetable garden “real estate” is about to open up as Island garlic crops near harvest. In my garden, eight rows of hardneck garlic take up about one-tenth of the garden space. The plants’ foliage has begun to yellow, in the wake of having their emerging scapes removed about two weeks ago. (After digging, the garlic plants are cured in a cool, airy space.)

I have already inserted some cabbage transplants between the rows of still-standing garlic. Cabbages need 24 to 30 inches of space around them to develop. There is room for rows of another crop: carrots, turnips, more beans, radicchio, broccoli, more kale — anything I would want to have as fall crops.

Most of these second-season crops should be seeded by mid-July to reach successful harvest. Other good succession crops are salad greens, Asian greens, beets, spinach, bush beans, sugar snap (mange-tout) peas, and summer squash, keeping in mind heat conditions.

Start weekly application of Bacillus thuringiensis (Bt) on Brassicas. It controls the caterpillars that blight this group, including broccoli, cabbage, kale, cauliflower, kohlrabi, Asian greens, and Brussels sprouts. Cucurbits are attracting squash bugs and striped cucumber beetles. These and squash-vine borers are very difficult to control. If you are deft, hand-picking in the cool of morning or evening, when insects are sluggish, is one means.

Continue to deadhead and deadleaf in the ornamental garden, and keep after weeds while they are small.

Roses, roses, roses

June roses have been exploding in wonderful abundance, and July looks set to be show time for the ramblers. Rosa rugosa, also called beach rose, has been, along with all the rest, in splendid bloom. Its scent on the fresh Island air, along with that of its less welcome, invasive cousin, R. multiflora, is a delight. Welcome to summer!

Rose sawfly larvae, skeletonizers of rose plant leaves, seem to have emerged later and had less impact on plants’ vitality and bloom quality. Bacillus thuringiensis (Bt) is ineffective against these caterpillar look-alikes because they are not Lepidopteran caterpillars but Hymenopteran larvae of non-stinging wasps. Japanese and oriental beetles have yet to make much impact. However, insecticidal soap, neem oil sprays, and horticultural oil all seem to give roses and foliage protection from these pests. Apply early or late in the day to avoid foliar damage.

Clean up rose petal drop where practical, to reduce the numbers of earwigs, sow bugs, and other such insects that find cover in the debris. Fertilize after bloom flush is past. I use two cups of low-number organic fertilizer — “soil food” — scratched in lightly per rose. Foliar feed and fungicide applications are made with tank or hose-end sprayers. In addition to fertilizing, deadheading roses encourages formation of more flower buds. With climbing roses, such as New Dawn, cut back laterals to about 12 inches.

Conservation goals

Rosa rugosa’s use as plant material in conservation areas and shore stabilization leads me to make the following observation about all such plantings: They often become nightmares for property owners and gardeners, and need to be entered into carefully and with forethought.

The reasons have little to do with the plant material itself and rather more to do with the idea that an area can be planted and left to its own devices. Why not? you say, “low maintenance” is just what I wanted!

In the past we did not have many invasives here. Today the Island hosts vast amounts of invasive exotic plants. Many formerly advocated plant materials, such as autumn olive and multiflora rose, have themselves become plant pests. Nursery stock has arrived on the Island from all over the country, in staggering amounts. It brings with it additional seeds and weeds. Some characteristics of invasive plants are their ability to out-seed, out-spread, and out-compete with the native plant cover.

Mass Audubon’s publication Connections recently featured a warning about mile-a-minute vine. Be on the lookout for it here. Arriving in Massachusetts in 2006, Persicaria perfoliata “sports leaves shaped like equilateral triangles and round, cup-shaped ocreae (or sheaths) which form at the nodes of the stems… the flowers are inconspicuous, but the clustered berries display a beautiful deep blue, each one containing a seed. This aggressive vine can grow up to six inches a day.” The seeds remain viable in soil as long as six years and can float in water for more than a week. Learn more at

When we plan for naturalizing and look for suitable plants, obviously we are looking for trouble-free plants, or planted areas, that can take care of themselves. When we plan and plant a thicket of low-maintenance, all-native cover it can and will host wildlife, a good thing.

The cover will also host the seeds of invasive plants, or maybe merely poison ivy, becoming itself infested, not such a good thing. There are problem areas in half a dozen gardens where we work, areas amounting to a steady encroachment by roots, stolons, and seed stocks that gobble up the owner’s property and cost countless hours and dollars to combat. Oriental bittersweet, black swallowwort (the Monarch butterfly killer), bindweeds, Japanese honeysuckle, phragmites: all these and more thrive in low-maintenance areas once their seeds arrive.

Regulations provide for the protection of conservation or shore zones in most towns, and conservation commissions are tasked with that protection. They often ask that the site in question be planted appropriately. I would ask that conservation commissions and landowners both take a careful look at their means and ends, and not create monsters in the pursuit of good management.

Slow Food MV

On August 23, Slow Food MV will present Terra Martha, an Evening with Carlo Petrini, the founder of Slow Food International, at the Tabernacle. For additional information see