Your ‘When To’ List

One of the questions many home owners have concerning their landscape is, “when should I do this, or do that? ” Here’s a brief guide that gives you the best time of the year to perform some common home landscape chores.

In the home landscape there are seasons to reap and seasons to sow. Here’s a few tips on the best time of the year to take care of a few important landscape maintenance items.

Lawn Fertilization
To keep your lawn in tip top condition you should schedule to apply fertilizer sometime between September 20th and October 20th and a repeat application approximately one month later. This applies to lawns made up primarily of Kentucky bluegrass, tall fescue, perennial ryegrass, fine fescues, or any combination of the four. If you have one of the rare lawns of zoysiagrass you should target your fertilizer application for sometime between June 1st and August 1 St. Most zoysiagrass lawns only require a single fertilizer application per year.

Tree Pruning and Trimming
If you need to prune off a single limb, the one that keeps hitting you in the head when you try to mow under it, you can prune it out anytime of the year. If you are planning a substantial amount of pruning on a single tree, removing more than 20 percent of the total branch area, you should carry out this pruning operation when the tree is dormant, sometime between mid December and mid February.

It’s nice to prune evergreens, such as holly and pines, in December and use the prunings for house decorations for the holidays. One warning here, pines and spruce are two trees that resent severe pruning. If you cut branches back beyond the point where any needles remain, you are unlikely to have new shoots appear on these branches. They will remain as ugly, wooden stubs. Most other plants will eventually produce new shoots from the cut branches, but pines and spruces won’t.

Tree and Shrub Fertilization
This has been the source of much confusion over the years and I have heard and read many differing recommendations. My current belief is that the fall, sometime between October 1st and November 15th, is the best time to fertilize trees and shrubs here in Maryland. If your tree is well established, more than ten years old, and is in a lawn area, the normal fall lawn fertilization will provide adequate nutrients to the tree.

If the tree is young and you want to maximize growth, you should have a wide clear or mulched area surrounding the tree and apply the fertilizer there. A ten foot tall tree should be surrounded by a cleared, or mulched, zone that’s at least ten foot in diameter. I know this is much larger than what you normally see, but this will help maximize your new tree’s growth rate.

Groups of shrubs should also be surrounded by a cleared, or mulched, zone and this is where you want to broadcast the fertilizer in mid fall.

Bringing the House Plants In
If you have given some, or all, of your house plants a summer outside you will want to bring them back inside well before the first killing frost in the fall. In Prince George’s County the first killing frost averages on or about the 20th of October. Some years it’s a bit earlier, some years a bit later. I don’t like to gamble with my plants and I schedule them to begin coming back inside in mid September with the entire move completed by the end of the month.

I move about 200 cacti plants outside every summer so I know all about the “great plant shuffle.” It’s dangerous to try and schedule the move at the very last moment. Just when the weather forecasters are predicting that first killing frost you may have a lot of other things to do, so get the house plants in a bit earlier, by the end of September.

Putting the House Plants Out
In Prince George’s County the last killing frost in the spring averages on or about the 1st of May. Since it is a real hassle to have to move the plants back inside right after they have been moved out, play it safe and wait at least two weeks beyond the average last spring frost date. This schedules the putting out of the house plants sometime after May 15th. Obviously if you live in the far southern end of the County, Brandywine or Accokeek, you can sneak things in a few days earlier, and if you’re up north, in Beltsville or Laurel, you may want to wait a bit later than May 15th to be on the safe side.

Remember, the one thing we can be sure about concerning the weather, is that we can never be sure about the weather.

When to Divided Perennials
If you are growing hosta, daylilies, chrysanthemums, or a host of other clump forming perennials, sooner or later you will want to dig up the clump, divide it into smaller parts, and replant. The best time of the year to tackle this chore is early fall, sometime in October, after the foliage

has deteriorated and turned brown, or in early spring, sometime between March 20th and April 20th, just as the new growth is appearing. One exception to this rule is the bearded iris, or flag lily as my mother use to call them. These are best divided in August when the plants are dormant and the hot, dry weather reduces the chances of rot in the fatty, fleshy rhizomes.

Applying Crabgrass Preventers
Crabgrass is the single most serious weed in our lawns and it is also relatively easy to prevent through the use of a preemergence crabgrass weed killer. These materials have to be applied prior to crabgrass seed germination. In Prince George’s County crabgrass seed usually sprouts in early April so target your crabgrass preventer application for the last two weeks in March.

Depending on the active ingredient in the crabgrass preventing product you use, you may be required to apply a second application in June. Read and following the product label carefully and you’ll get the maximum benefit from your product.

Getting Help for Other Yard and Garden
Timing Questions
If you have questions concerning gardening chores that were not covered in this article, you can call the University of Maryland Home and Garden Information Center. The Center is open on Monday through Friday from 8:00 am until 1:00 PM. You can reach the center from any location in the State of Maryland via their toll free phone number: 1-800-342-2507

Article supplied by MD Cooperative Extension.

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