Daniel Gill, Merrill, Thomas A. | 8/30/2007 2:05:42 AM
By Dan Gill
LSU AgCenter Horticulturist
September is a transitional month in the vegetable garden. Toward the end of this month we should see some relief from the intense heat of mid- to late summer. Still, September can be quite warm, and daytime highs in the 80s are common well into October.
Most warm-season vegetables, like tomatoes, cucumbers and peppers, should have been planted back in August for fall production. Now, we are primarily focusing on planting cool-season vegetables, particularly in North Louisiana. In the southern portion of the state, however, adventurous gardeners may plant warm-season vegetables as late as the first week of September.
Vegetable and herb gardening seasons can be roughly divided into the cool season and the warm season. Vegetable gardeners must be especially attuned to the seasons and carefully observe the proper planting times for vegetables. Planting times relate to a variety of factors, but temperature is a major consideration.
Warm-season vegetables cannot withstand frost without significant injury or death. They are grown from about March through November, divided up into the spring planting season (March and April), the summer planting season (May, June and July) and the fall planting season (August).
Cool-season vegetables are grown roughly from September to May. They need lower temperatures to perform their best and are able to tolerate the below-freezing temperatures of the winter cool season. Cool-season vegetables are planted primarily in the late summer and fall (September, October and November) and the spring (February and March).
Plant bush snap beans the first week in September so they will have time to produce a good crop before cold weather. Bush varieties produce faster and concentrate their harvest in a shorter period of time than pole beans – making bush beans preferred for fall planting.
As we move into the cool season, root crops such as carrots, radishes, parsnip, rutabagas and turnips are an important part of the garden. Root crops are always direct seeded – never transplanted. The tiny root first produced by the seed eventually develops into the edible root. It is easily damaged when the seedling is young, and any damage will cause a deformed, poor quality final product.
Plant seeds of bulbing onions, bunching onions and leeks this month. Sets (small bulbs) of bunching onions and shallots also may be planted this month, but do not plant sets of bulbing onions until early December. Onions, shallots, leeks and garlic (garlic bulbs are planted next month) are long-term residents in the cool-season vegetable garden and, and those harvested for their bulbs will not be ready to harvest until late May or early June of next year. Green onions (scallions) and green shallots are harvested through the winter and into the spring.
There also is work to be done in the herb garden this time of year. Regularly remove the flower spikes of basil to encourage plants to continue to produce leaves. Ultimately, the plants will begin to wind down. But basil transplants still could be planted into the garden now for a quick late crop.
Herbs such as sage, lavender, thyme and catnip should begin to revive as the weather gets cooler. Remove any dead parts and fertilize lightly to encourage new growth. Generously harvest herbs that have grown vigorously during the summer. Dry or freeze the extra harvest or share it with friends.
This month can be hot and dry, and with new plantings going in, you should pay careful attention to the water needs of the garden. Newly planted transplants and seed beds are especially vulnerable to drought conditions and may need frequent (even daily) irrigation. As seeds come up and transplants become established, water deeply and less frequently to encourage a deep root system.
High population levels of insects are around now, so be vigilant and treat problems promptly. If a crop is about to finish up, such as okra is now, you generally should not be as concerned about controlling pests on it as a vegetable crop that has more recently been planted.
Caterpillars can be particularly troublesome in the fall garden. Regular applications of Bt will keep their damage to a minimum. Control white flies and aphids with light paraffinic oil, such as Bonide Year Round Oil or All Seasons Oil.
The LSU AgCenter’s Louisiana Vegetable Planting Guide is an excellent reference, which includes year-round planting dates for vegetables. Contact you parish LSU AgCenter Extension office for a free printed copy or view it online at www.lsuagcenter.com. Type Louisiana Vegetable Planting Guide in the search box on the Web page, or go directly to http://www.lsuagcenter.com
Vegetables/planting_guide/Louisiana+Vegetable+Planting+Guide.htm to view or print a copy of the guide.
Vegetables that can be planted this month include beets, broccoli, cabbage, carrots, cauliflower, Chinese cabbage, collards, English peas, snow peas, Irish potatoes (plant small, whole potatoes saved from the spring crop), kale, kohlrabi, leek, lettuce, mustard, onions, radishes, rutabagas, shallots (plant sets), snap beans, Swiss chard and turnips. Herbs to plant include rosemary, parsley, chervil, sage, thyme, fennel, oregano, French tarragon, chives, garlic chives, borage, burnet, cilantro, mints, lemon balm, lavender, catnip and dill.
Get It Growing is a weekly feature on home lawn and garden topics prepared by experts in the LSU AgCenter. For more information on such topics, contact your parish LSU AgCenter Extension office or visit our Web site at www.lsuagcenter.com. A wide range of publications and a variety of other resources are available.