Master gardener adviceon fall fertilizing

Although the first average frost date for much of northwestern Nevada is Sept. 15, the weather that follows is generally sunny and mild for a few more weeks.

In the bright fall sunlight, photosynthetic activity remains high, sending food to plants' roots for winter storage. This stored food helps plants survive through the winter, creates better root initiation and produces a good, early spring green-up, without the excess top growth that results from spring fertilization. The new root growth produces a healthier plant through the following summer.

Fall fertilization of lawns also provides these same benefits, without requiring the extra mowing chores that accompany spring fertilization. Use a slow-release lawn fertilizer while the warm weather continues. Be aware that products that rely on soil microbes to release nitrogen won't work as the soil and air temperature cools.

Ammonium sulfate, 21-0-0, or a balanced 16-16-16 or 20-20-20 fertilizer, work well for fall lawn fertilization, especially if the products have added sulfur. These are very effective after the first few freezes, through October.

Most fertilizer companies sell more expensive fall lawn products, but these work just as well. Avoid weedkiller/fertilizer combinations, as they contain more weedkiller than fertilizer and can damage shrubs and trees.

As you mow, leave the grass clippings on the lawn, if they aren't long and matted. They will put extra nitrogen back into the soil. Don't bother fertilizing the lawn once it turns brown. Fertilizing the lawn now will make it look great in the spring.

Wait to fertilize trees and shrubs until after a hard freeze or two to avoid encouraging new growth this late in the season. I like to use a 16-16-16 with added sulfur.

By fertilizing in the fall and deep watering at least once a month from October through March, trees and shrubs stay strong and will put out extensive growth come spring.

Feed flowers, including roses, and vegetables with an organic fertilizer now during this warm weather to give them a boost.

Besides fertilizing, here are a few more fall tips:

-- Remove some leaves from tomato plants to get the fruit to ripen.

-- Plant a late crop of radishes, beets, lettuce, cilantro, parsley, and other cold-tolerant crops.

-- Harvest apples when a slight lift-and-twist motion drops the apple into your hand.

-- Pears can be harvested green, as they will readily ripen off the tree.

For more information on gardening, contact me, 887-2252 or, or your local University of Nevada Cooperative Extension office. Check out many useful horticulture publications at "Ask a Master Gardener" by e-mailing

-- JoAnne Skelly is the Carson City/Storey County Extension Educator for University of Nevada Cooperative Extension.


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