Garden Notes: Death into life

Studying up on soil biology and soil health.

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As the 2022 gardening year seemingly winds down, it can be understood as actually the beginning of the next one. Gardening is a cyclical process: What we do now is to the garden’s benefit, and is the beginning of the coming year.

Gardeners must debate with themselves as to whether skeletal garden remains are left as food and shelter (seedheads, stems, debris) over winter for wildlife and arthropods, or whether an antiseptic cleanup approach is going to prevail. Like the ferns pictured, some are beautiful in a state of decay.

Whether cleanup is selective or wholesale, composting all the organic debris that results from it is the answer: Not only is this environmentally sound, but it is also an assist to your soil and garden.

Winter’s rest and repair

Shorter days assist processes that have been ongoing for longer than humans can imagine. For all trees and plants, what happens now in seasons of cooler temperatures and fewer photons is rest and repair, without the stress of responding to light-driven cues to photosynthesize and put out aboveground growth.

In deciduous trees and shrubs, the nutrients present in foliage have receded to the root zone. The xylem and phloem vascular processes become like a just-barely-ticking-over system of dormancy, only enough to keep next year’s buds viable.

For evergreens, however, there is no suspended animation. Circulation, limited photosynthesis, and transpiration continue. The maritime climate’s freeze/thaw cycles and drying winter winds may induce a great deal of moisture loss, termed “winterkill,” when they occur in them. Watering deeply now, applying mulch to root zones, plentiful rains, and spraying with an antidesiccant help evergreens to manage the up-and-down type of winter we increasingly experience here, but especially so if plantings were recently installed.

Speaking of evergreens, this is a good time to inspect rhododendrons for pruning needs. Mature plants may have grown outward, in a pattern commonly vulnerable to splitting and breakage under heavy snow and ice load. Center the mass by shortening those limbs that look as though they are overextended.

Soil repair

As Mitchell Posin of Allen Farm says, the phrase “soil biology” is often incorrectly used. What is usually intended is instead more properly called the “soil biome,” i.e., the life forms of the soil. 

“Soil biology” is the study of soil: its makeup, functions and biome. We used to call soil “dirt,” a word that connotes filth, grime, and obscenity. Some clever person realized that there was more than that going on in the ground beneath our feet, and started looking more closely. Thus was discovered the soil biome, the living component of soils that enables all plant growth.

Soils are alive with billions of organisms, viral, bacterial, and fungal, many still unknown and unnamed, that enable all life on earth and that enable plant health: the soil biome. For food gardens as well as ornamental gardens and lawns, this is the time to focus on your soil’s biome, as well as, incidentally, becoming a backyard soil biologist. 

Soil testing is always recommended for more information about what is taking place below ground; find testing labs at bit.ly/soiltesting_MVT. You identify the use of the sample you are submitting: lawn, orchard, ornamental, or vegetable garden. While awaiting results, there are several options for feeding and building your soil’s biome: plant a cover crop; mulch the surface; apply aged animal manure; or top-dress with a thin layer of compost.

Cover cropping for winter: Use a “winter soil builder mix,” or winter rye. Mulch materials could include straw, grass clippings, leaf and pine needle mulch, compost, and cardboard. Some of these may introduce weeds into the garden, but down the road, high organic content will make weeding far easier.

When I refer to fertilizer, I always try to insert the term “soil food,” to emphasize that it is feeding the soil to make it healthy that enables plant growth, not applying some chemical “jet fuel” fertilizer to force it. Please use slow-release organic “soil food” fertilizers: good for children, for pets, and for water quality (vineyardconservation.org/vineyard-lawns). 

Containers, transport, citrus

It means a lot of lugging: summer vacation outdoors is about to be over for container plants, such as the camellias, hibiscus, fuchsias, holiday cactus, and citrus, soon to return inside for the winter.

How effortful it is to bring these big babies indoors was what a friend and I were commiserating about outside the grocery store. I happened to have a nursery supply catalog handy, so we took a look to investigate the properties of the GardenGlide device. It is a possibility, although I am not sold, compared to using a hand truck. My husband built dollies for many of our biggies.

Maintaining container citrus is both pleasurable and a challenge for those who have the space and desire. The plants are handsome and utilitarian. The flower scent is a joy on winter days. The fruit, if the conditions align to produce it, is always welcome, a small triumph.

These citrus do not remain petite, to live on kitchen counters, although Logee’s most recent catalog features a hanging container plant citrus, the sweet orange ‘Cipo.’ It is described as having a weeping habit that gives it a cascading form, fruiting reliably every year, with flowers and fruit forming at the ends of trailing branches.

However, with citrus, effort accompanies pleasure. They are receiving a douching before being brought inside. Whitefly, aphids, and scale insects enjoy them, requiring control measures on a regular basis. Fungus gnats and vine weevils may inhabit containers’ soils. I use insecticidal soap and horticultural oil, which are pretty good at managing, but not eliminating, these insects.

In the garden

Informal protection can be devised for plants that might make it through the winter with just a small assist. Hay bales, old storm windows, and my favorite, the brick turret shielding the Mid-Island Repair rosemary plant, may pull plants through.

Prune evergreens such as yew, ivy, boxwood, and holly. Stick in bowls with pinholders; keep water topped up. Use as centerpieces. Some will root. Voilà, more plants.