Garden Notes: Summer conditions, good and bad

If roses are scary, consider hypericum.

0
Susan Safford

July is daylilies and rambler roses lining roadsides, and privet and honeysuckle scenting summer evenings. Gardens leap into prime time; there is so much happening, both at ground level and above, where lindens and catalpas are loaded with blossom.

A red rose

This year’s conditions have led to a glorious rose show, perhaps stimulating gardeners without roses to desire one, or more. The red rose is a symbol, a trope: While there are hundreds of glowing cultivars, in my own gardening practice they have not figured prominently.

However, I do have a longtime favorite, the classic ‘Dublin Bay,’ (McGredy, 1974): blood-red and velvety, a short and rather stiff climber that is healthy and repeats well. It may be trained onto a fence or arbor, and is perfect in many ways, only lacking scent.

Now a new red rose has entered my life. Suppose you’d love a real red rose and have no fence or arbor in your garden? The easy-care, red shrub rose ‘Kashmir’ is one of the Easy Elegance series, bred by Bailey’s Nurseries. They sent me several sample plants of the series to trial. Lacking a spot for it, I let ‘Kashmir’ sit in a pot over two winters in an unheated shed before planting it.

‘Kashmir’ shook off the abuse after planting, and has been covered with large, crimson blossoms for weeks now (they age purplish/red). Stems are not hybrid tea cutting length, but make a respectable cut flower. The foliage is dark green and healthy. It is an “own-root” plant, not grafted, as were many 20th century hybrid tea types. It is expected to attain a size of three to four feet high by two to three feet wide, and so may be used in full sun as a foundation planting, hedge, or standalone plant in the mixed border. If red roses are your trope, do check out ‘Kashmir.’

Hypericum

While roses are wrapped in an aura of challenge in the minds of many gardeners, despite the new generation of easy and beautiful shrub roses, there is a free-flowering family of shrubs for July-and-longer that is largely trouble-free. The family is Hypericum, and several shrub species are available, and do very well in Island gardens. Deer-resistant, tough, and drought-adapted to sandy soil once established, pollinator-friendly hypericum also makes a delightful subject for seaside plantings.

Plant family Hypericum has almost global distribution; there are many, many species. However, we mostly see less than half a dozen in trade here. People familiar with herbal usage may recognize the name hypericum as the botanical St. John’s wort. Herbaceous perennial hypericum, H perforatum, is a naturalized European plant of sunny Island byways, recognizable by its five-petaled yellow flowers.

The hybrid Hypericum x. ‘Hidcote’ is one of showiest in bloom, a shrubby form capable of three- to four-foot height, and the one most likely to be seen in gardens. The large golden-yellow flowers with prominent stamens are two or more inches across, and the clean foliage is a pleasing blue-green. Hypericum inodorum ‘Kolmapuki’ retains burnished pumpkin-colored seed capsules after flowering that have now become a staple of the cut-flower industry. H. calycinum is lower-growing, most often used as a groundcover and bank holder. H. kalmianum is a seed and nectar source, a good choice for eco-planting. H. frondosum is another popular shrub form.

Heat and humidity

We were anxious for summer; now it is here. Guess what? It is not all easy living and delightful days in the garden. Hail is certainly a damaging and unusual problem for Island gardens. Warm soils are heaven to insects “summering on the Vineyard,” such as oriental beetles, which emerge at night to chew ornamentals and vegetables.

Among other afflictions, the heat and humidity create everything necessary for fungal powdery mildews to proliferate. Plants experiencing stress, which may take many forms, are most likely to be afflicted. Overwater, dryness, too much sun, too much shade, poor air circulation — all are stress factors that could be “right plant, right place” issues, leading to infestations.

In ways similar to antibiotic resistance, fungicide overuse has been implicated in many developing and persistent soil problems. Some scientists fear that overuse of fungicides on crops is contributing to the increase in deadly drug-resistant fungi infecting humans, such as Candida auris. Although perhaps more critical in agriculture than gardens, fungicide overuse is to be avoided by all careful gardeners.

Fungi are, despite their potential to cause problems, integral parts of the flora and fauna of soil communities. All components are needed in functioning soil ecosystems. Attempts at eliminating fungi are doomed to failure — microbes always adapt and gain resistance — but more important, they miss the point of soil ecology and healthy soils.

Sprays and drenches that work not as antibiotics but as physical barriers are one solution. Compost teas, horticultural oils, antidesiccants: all are worth giving a try. Try analyzing what else may be done to improve the conditions and minimize the stress of the afflicted plants.

In the garden

Keeping up with all the tasks in the heat is a tall order. Water what needs it; mind the dangers of overirrigation. Deadheading of both annuals and perennials is what keeps the show going. Cleanup of petal/leaf drop is daunting, but well worth the effort, especially with large flowered daylilies, whose spent flowers wreck an otherwise pretty show.

Keep up with succession sowings. A short row of bush beans, planted every other week, may be better than an endless row that must be stripped. (Unless you are processing — then you want lots ready at once.) Compost pea-straw. Carrots are one of the best fall crops; weed out and prep a fine seedbed for the small seed.