Ideal Time to Fertilize Lawns

September, October and November are the best months for fall lawn fertilization. When you fertilize during this time period depends upon the condition of your lawn. If you have not watered your lawn this summer, fertilize as soon as the rains start. If your lawn is green and growing well, wait a month or so. Fertilizing in early November will keep your lawn beautiful through the winter without increasing the growth rate.

One of the great benefits of fall fertilization is that it not only gives immediate results, but it also carries over into spring. Fall is the time when grass makes a lot of new growth under the ground. New roots and crowns cause turf to thicken. Food produced by the leaves is stored for the winter and next spring.

Most brands of lawn fertilizer have developed formulas for fall fertilization. They generally contain more potassium which makes grass more resistant to winter weather. However, I have found that almost any lawn fertilizer works well in the fall. Research has shown that nitrogen is taken up by grass roots and used to make amino acids which are stored in grass crowns and roots. These amino acids are available for immediate use in early spring when soil is too cold for roots to take up nitrogen. The result is a more attractive spring lawn.

Read the “guaranteed analysis” label to make sure lawn fertilizer contains iron. Iron causes grass to turn dark green, sometimes almost over night.

Fall is also an excellent time to apply lime to lawns. I like to lime my lawn every 2 to 3 years to reduce soil acidity.

Wait until late November to fertilize trees and shrubs. By then, top growth has become dormant, but roots can continue to take up fertilizer until the ground freezes. Stimulating new growth now will make some of our more sensitive broad leaf evergreens such as Mexican Orange (Choysia ternata), Escallonia, and Viburnum ‘Spring Bouquet’ more susceptible to winter damage.

Fall Is a Great Time to Plant

Now through November is the time to plant spring blooming bulbs such as daffodils, tulips, crocus and hyacinths. I have had the most success with daffodils. Moles do not eat them and they multiply so that you have more flowers every year.

Now is an excellent time to plant trees, shrubs, vines, ground covers and perennial flowers growing in containers. If you want to move plants in your own landscape, wait until November.

Pansy is the ideal annual flower for fall, winter and spring bloom. Planting in September will give plants time to become established before cold weather.

Several vegetables can be planted from seed to harvest this fall, winter or next spring. These include radish, carrot, green bunching onion, spinach and leaf lettuce. Started lettuce, spinach and bunching onion plants are available in some full service nurseries and garden stores.

Now is the very best time of year to plant a lawn from seed or re-seed areas in an existing lawn which are not doing well. Soil is warm but air temperatures are cooling, which is ideal for seed germination and growth. Fall rain does most of the irrigation for you. Weed seed germination rate is less than 10% of the spring rate.

Before re-seeding you can spray coarse wild grass with Roundup. Then use an aerator or thatch machine to loosen the top of the soil. It is important for grass seed to be in contact with the soil. I like to mulch with a quarter to half inch of bark dust to hold moisture and make sure seed is covered. Soil should be kept constantly wet for a month after planting. This may require twice a day watering when there is no rain.

We can do any of these planting jobs for you including helping you design an area or make plant suggestions. If you would just like some suggestions or ideas, call or email. The first consultation is free for newsletter readers in the local area.

Fall Weed Control Works Best for Perennial Weeds

If you have perennial weeds such as dandelion, clover, Canada thistle, ivy or blackberries, now is the best time to apply herbicides. Plants are sending food produced by the leaves down to the roots, so herbicides are transferred more quickly to kill the entire weed. Use liquid lawn weed killers or granular weed and feed on your lawn. Roundup or similar products containing glyphosate are effective for general weed control where you can avoid spraying leaves of your ornamental plants. Roundup will not damage bark so it can be sprayed around trees. For woody weeds such as blackberry and ivy, brush killer is more effective.

Reduce Irrigation

Even if we do not get much rain in September, the cooler temperatures and shorter days reduce plant and soil water loss. If you have an automatic sprinkler system, it is time to reduce the amount of water applied. It is better to lengthen the interval between irrigations than to cut down on the number of minutes for each irrigation.

Is Fall a Good Time to Prune?

We live in a climate where most plants can be pruned year round. There are a few plants which should not be pruned in the fall. Mexican Orange (Choysia ternata), Escallonia, and Viburnum ‘Spring Bouquet’ are more susceptible to winter damage if pruned in the fall. Pruning may stimulate new growth which is more susceptible to freezing. Most spring flowering shrubs, such as Rhododendron have already set their flower buds for next spring. Pruning now will remove some of those flowers. Fruit trees are best pruned in the late fall or winter with a followup in early summer. All other trees and shrubs can be pruned now. This is an excellent time to prune hedges because they are through growing and will stay neat until next spring or summer.