Tidewater Gardening - September 2010


Hot Enough For Ya?
K. Marc Teffeau


After going through some record heat and drought in July and August, cooler temperatures will hopefully start up this month. How hot was it? It was so hot that my wife and I went to Desert Springs, California, to escape the humidity. I attended a professional conference there the first part of August. Temperatures were 110 degrees with 10% humidity. It is a dry heat but it was still hot! The desert has its own beauty and after what we experienced this summer, maybe we need to start thinking about xeriscaping (landscaping and gardening in ways that reduce or eliminate the need for supplemental water from irrigation).
Your turf areas may need some renovation and renewal after this past summer. September is a good time to seed and lime the yard. A fall application gives the lime several months to break down before the spring growing season. Liming is one of the least expensive practices that you can do that will yield the most results in the long run.
Our cool season turfgrasses such as the improved turf type tall fescue does best at a soil pH of 6.0 to 6.5. Since many of our soils here on the ‘Shore are clay based in nature they naturally have a lower pH. If I had the choice between fertilizing and applying lime, I would always lime – if the soil test indicates that it is needed.
Soil testing your lawn is like getting a blood test during a medical check up. It establishes a baseline as to the pH and nutrient levels in the soil. With all the emphasis on reducing chemical inputs into the lawn because of concern about the Chesapeake Bay, a soil test is a must before you lime or fertilize your lawn.
Unfortunately, because of budget issues, the University of Maryland closed down its soil testing lab in 2003. You will either need to go through the University of Delaware or a commercial lab. A list of regional soil testing labs can be found at the University of Maryland Home and Garden Information Center at www.hgic.umd.
I recommend soil testing lawns every three to four years. If you are hiring a commercial lawn care company to renovate or reseed your lawn area, insist that a soil test be done before they begin to apply fertilizers and lime.
A correct lime application to your lawn based on a soil test will maintain a correct pH for up to six years, possibly more, depending upon your soil type and how often you fertilize. How rapidly the pH falls depends largely on the amount of nitrogen fertilizer that you apply annually. The less you apply, the slower the pH drops. An annual application of lime is unnecessary and can actually push your soil pH too high and make other soil nutrients unavailable to the turfgrass.
Limestone may be put out as a finely ground powder or in a pelletized form. You want to use agricultural lime (dolomitic or calcitic) and not burned or hydrated lime. These last two forms of lime are caustic and result in a quick but not long lasting pH change. Agricultural lime is safe to use and is nontoxic to plants, people or pets. It is simple to get uniform coverage with powdered lime by spreading half in one direction, then spreading the other half in a perpendicular (crisscross) pattern.
Pelletized lime is easier to spread and doesn’t produce an irritating dust, but it may not give uniform results. Pelletized lime should be applied to the soil surface and watered-in before tilling if you are seeding or reseeding a lawn. If the pellets are incorporated intact, rather than being dissolved with water first, localized pockets of neutralized soil may occur. You will probably find that pelletized lime costs about twice as much as powered lime but it is still a cheap investment to make in the care of your turn. If you are liming an existing lawn, watch the weather report and try to lime a day or two before rain is predicted.
To over-seed an existing lawn, apply both lime and seed, but delay fertilization for a couple of weeks. During this time, irrigate thoroughly every couple of days, if good drenching rains do not occur. To repair bare spots, treat just like you were over-seeding, or better yet, sod the spots instead of seeding.
In the September landscape, as the nights become cool, caladiums will begin to lose leaves. Dig them up, allow them to dry, and store them in a warm, dry place. This space can be replanted with Christmas peppers or Jerusalem cherry plants that are easy to grow from seed in pots or with mum transplants that have been grown to flower size. Perennial phlox should be divided about every third or fourth year. Early fall and early spring are the best times to plant and transplant them. Divide big clumps into thirds.
Plant roots of both garden and tree peonies in September or early October so they will have time to become established in the soil before winter. Dig a hole 18 inches across and 18 inches deep for each tuber. Space the holes so that the plants will be at least 3 feet apart. Make sure the roots are buried only 1½ to 3 inches below ground level. Deeper planting keeps the plants from blooming.
As you plant your spring bulbs, remember that a mass planting of one flower type or color will produce a better effect than a mixture of many colors. Flowers of bulbs stand out more vividly if displayed against a contrasting background. For example, white hyacinths among English ivy, yellow daffodils against a ‘Burford’ holly hedge, or red tulips towering over a carpet of yellow pansies.
Sowing seeds of hardy annuals, such as sweet alyssum, pinks, and sweet peas, now will give the seedlings time to get established and develop good root systems before the coldest part of winter. This gives them a head start on growth and flowering next spring.
September is an excellent time to establish new perennial flower beds. Dig, divide, and replant overcrowded beds of cannas, day lilies, violets, and shasta daisies. Spread a liberal amount of organic matter, such as compost and bulb fertilizer, evenly over the area. Mix this into the soil at least 6 to 8 inches deep. Space divisions at least 1 foot apart in all directions so that root competition will not be a problem for several years.
Don’t forget to add lilies to the plants in the perennial beds for many years of beautiful flowering. Modern hybrids are available in many colors and grow from 2 to 6 feet tall. American-grown hybrid varieties have less trouble with viral disease than the old specie types.
September is a great time to plant shrubs and trees in the landscape. By planting in the fall, your plants do not endure the stressful summer heat during establishment and have time to form sufficient root systems before the onset of winter dormancy.
For established deciduous trees and shrubs in the landscape, wait for their leaves to begin to drop before fertilizing them. This signals dormancy, when no new growth will be stimulated that might not harden off prior to cold temperatures. However, roots are active until soil temperature drops below 40◦, so nutrients will be taken up and used by the plants to develop a stronger root system.
Allow plants to finish the summer growth cycle in a normal manner. Never encourage growth with excessive pruning at this time as plants will quickly delay the hardening process that has already begun in anticipation of winter several months ahead. New growth can be easily injured by an early freeze.
Don’t forget the vegetable garden. If you haven’t already, sow some lettuce and other greens seeds in the vegetable garden. They will come up and give you a nice basis for salads later on in October.
Also, don’t forget to seed root crops like beets, carrots, turnips and parsnips. They might not get very big in the fall, but they do overwinter if you cover them with some straw, and you can harvest them in the spring. Harvesting some of the crop in the fall is nice however, because these root crops don’t get big and they stay tender. Ever eat a beet from the garden that is the size of a baseball? They tend to be rather woody.
Happy Gardening!!