How Gardens Grow
by Ruth S. Foster
One of the joys of summer is making time to read technical journals and publications that pile up on the floor that have been saved for these less hectic, lazy days to get new understandings of how gardens grow.
Plant Health Care
As "power gardening" has become a major hobby, more and more people want lower care plants and tougher plants that don't curl up and die if you look cross-eyed at them. Current emphasis is on the latest philosophy which is called Plant Health Care. Its focus is the theory that keeping plants healthy is most important, and it promotes the idea of "the right plant for the right place" for that is the secret of lower maintenance and longer life.
Begin with the environment: The advice is to first assess the environment that you actually have. Check the light, the soil, the wind, the rainfall, the high and low temperatures in the year. Then plant something that will thrive there. For instance, if the soil is naturally acid, don't spend each year spreading lime trying to make it like the White Cliffs of Dover. Instead plant acid tolerant Japanese holly, bayberry, blueberry, sweet fern, concolor fir, white pine, Japanese andromeda, oaks, rhododendron, and Swiss stone pine. They will love your soil.
Think about the mature size of what you plant. Choose plants that will be the right size when fully grown. It stands to reason that if you want a small tree, such as under electric wires, don't plant a giant of the forest. Instead try Japanese lilac tree, carolina silverbell, magnolia or Kousa dogwood. These all stay under 30 feet, have few pests, and don't require spraying. Another possibility is "Donald Wyman" crabapple, which is resistant to defoliating apple scab and cedar apple rust. Or consider Siebold viburnum, a large shrub which can be trained into a handsome small tree.
For salt contaminated areas: there are many salt resistant plants. Some of the nicer ones are inkberry, blueberry, mountain andromeda, juniper, shadbush (Amalanchier), summersweet (Clethra), bayberry, white oak and eastern red cedar. It's easy to recognize salt injury. It shows on the leaves as a dead brown crispy edge and is particularly noticeable on Norway maples planted on the sidewalk in late summer.
Tips for better tree planting: In normal locations don't stake trees with stiff wooden posts and rigid ties. When the trunks sway they develop stronger and thicker. Also don't swath the trunks with paper tree wrap because bugs and fungus thrive when cool and protected under the wrap.
Tips for fertilizing: The best time to apply fertilizer is late August into September. The rationale is that leaf growth has stopped, but root growth is just beginning. Healthy roots are the key to healthy plants. The second best time to fertilize is early spring just before new shoots appear. Except for a few lawn conditions and trees with compromised root areas, surface application of granular fertilizer works just as well as other more expensive methods like drilling, soil injection, trunk injection and fertilizer spikes.
Early Fall Problems
Tomatoes: There are fewer tomatoes when there hasbeen a heat wave. Tomato buds won't set fruit when the temperature is above 90 degrees but as the weather cools, they begin to form fruits again. It takes about 6 weeks from fruit set to harvest. About one whorl of blossoms is produced per week.
Slugs: In the cool fall weather, the slugs come out again, and they love ripe tomatoes. If you find holes chewed in red fruits, it's time to use slug bait. The only one that can be used with food crops is the pesticide metaldehyde. (But not combined with more poisonous sevin, which is for flowers only.) There are lots of home remedies for slugs, which can be tried and sometimes they help. However, in controlled university trials, only poisonous metaldehyde slug bait was proven effective in reducing damage levels. Caution: Never use such bait where children might eat it.
Skunks and Japanese Beetle Grubs: Also in fall, holes that appear in the lawn are from skunks digging at night for the beetle grubs. To check, cut a one foot square in the lawn and roll the grass back. If you see white, fat, c-shaped grubs about an inch long, then you know for sure. It's not necessary to treat the whole lawn, only the "hot spots" where the grass is browned, and only when there are more than 8 or 10 per square foot in the hole. Insecticides may be applied with the fall fertilizing. Check with your local extension service or agricultural university for the insecticides currently approved.