September Gardening Tips
Sow seeds of snapdragons, dianthus, pansies, and other winter flowers in flats for planting outdoors during October.
Continue to dig and divide spring flowering bulbs and perennials such as daffodil, iris, daylily, ajuga, liriope, and canna.
Prepare beds for spring flowering bulbs as soon as possible. Incorporate organic matter to improve drainage to prevent bulbs from rotting when planted.
Plant leaf and root vegetables such as broccoli, cabbage, cauliflower, radish, spinach, and lettuce late in the month.
This month or early next month, sow seeds of wildflowers into weed-free, well-tilled soil.
Applying fertilizer to warm season turf grasses in the fall is the most important application of the year. Use water soluble fertilizer high in nitrogen and potassium and low in phosphorus during the last two weeks of September.
Sow or over-seed cool season grasses such as fescue and rye, but remember, if you apply any pre-emergent weed killers to your lawn, newly applied grass seed will not germinate.
Rejuvenate heat-stressed flowering annuals, perennials and roses for the fall season by lightly pruning and fertilizing them. This includes (but is not limited to) geraniums, petunias, begonias, chrysanthemums, lantanas, verbenas, roses and salvias.
Prune out dead or diseased wood from trees and shrubs. Hold off on major pruning until mid-winter. Pruning now will stimulate tender growth that may be damaged by frost.
Root prune established trees and shrubs that you intend to move this winter. This allows them to establish new roots within the zone of soil that will eventually be moved with them. Do not cut any taproots at this time.
Don’t allow plants with green fruit or berries to suffer from lack of moisture. Hollies will frequently drop their fruit under drought conditions.
Adjust watering schedule as daytime high temperatures decrease. Water to the same depth, less frequently.
Divided Bulbs by Helen Abresch, El Paso Master Gardener