Garden Don'ts, Part II

A fruits expert and professor in the Department of Horticulture, Gail Nonnecke, came up with several garden don'ts for homeowners.

• Don't plant fruit crops in poorly drained soils. They can't survive wet conditions for long periods.
• Don't apply too much nitrogen. Regular applications of small amounts of fertilizer are fine for most fruit crops, but too much nitrogen results in excessive vegetative growth and reduces crop yields.
• Don't uncover strawberries too early (see figures below). Strawberry flowers are sensitive to cold temperatures and can be damaged by a late spring frost. Uncover them as late as possible, typically mid-April in central Iowa (Fig 1). Wait until the new growth begins to yellow, then uncover.
• Don't select fruit types or cultivars that are not reliably hardy in Iowa. No one would expect an orange tree to survive an Iowa winter. Peaches, nectarine, and sweet cherries are also not reliably hardy in most parts of Iowa.
• Don't forget to prune fruit trees every year. Unlike shade trees, fruit trees need yearly pruning. In fact, proper pruning often makes the difference between small and large crops.
• Don't plant just one variety of apple. Most apples are not self-fruitful. Plant at least two different varieties for cross pollination and fruit set. Your ornamental crabapple might work - but why chance it?
• Don't attempt to grow blueberries in high pH soils. Blueberries require an acid soil pH around 5. In Iowa, most garden soils have a pH above 5. So, lowering the soil pH is essential to successfully grow blueberries.
• Don't leave the dead floricanes in the raspberry plantings in August. Remove the dying floricanes immediately after the last harvest. This reduces disease problems by removing the disease inoculum and improving air circulation.

Ann Marie VanDerZanden, a landscape design and construction professor in the Department of Horticulture, has a few suggestions to add to the growing list of garden don'ts.

• Don't underestimate the impact construction can have on an existing landscape. Changing the grade can create drainage problems. Trenching near a tree can destroy half the root system. Removing shade trees can burn the hostas and other plants that prefer shade. Limiting death and damage requires plenty of planning.
• Don't design the landscape without some sort of plan. You wouldn't go to the grocery store without a list, would you? The plan does not have to be elaborate, it just requires some thought.
• Don't forget that the landscape evolves as plants grow. As the landscape changes overtime, use this as an opportunity to change the plantings, design focus, etc. Some nice things happen in the landscape this way.
• Don't forget there is a difference between a plant that is "surviving" and one that is "thriving" in the landscape. Obviously, you want the plants that "thrive" - so do some research, make sure they are well adapted to the planting site.

The Coordinator for the Master Gardener Program in Iowa, James Romer, had these suggestions for the list.

• Don't plant warm season vegetables and annuals too early. It would be nice to be able to pick a ripe tomato for the 4th of July, but let's be realistic. This will take a lot of work with few guarantees. Reduce your risk by planting at the appropriate time for your area.
• Don't forget to read and follow all product label directions. This is especially important for pesticides and herbicides. A lot of research went into the amount, timing, types of plants, and way these products are applied - use it!
• Don't apply grass seed and pre-emergent weed killer at the same time. Ask a Master Gardener why this is a bad idea.
• Don't forget to sharpen the lawn mower blade 2 or 3 times a year. Dull blades tear rather than cut the grass and ultimately give the turf an unhealthy whitish appearance. Your lawn will thank you.
• Don't apply broadleaf herbicides on a windy day (unless you want to damage neighboring trees and shrubs).

I asked Richard Jauron who answers callers' questions for the Hortline to provide a few garden don'ts. A few of his suggestions for lawns include:

• Don't mow the lawn too short. Scalping the lawn weakens the turf by increasing the lawn's susceptibility to drought, pests, and weeds. Mow Kentucky bluegrass lawns at 2 1/2 to 3 1/2 inches - anything less is scalping!
• Don't bag your lawn clippings. This message has been out a while, but it always bears repeating. Grass clippings do not contribute to thatch accumulation. The clippings from your lawn are also a good source of nitrogen. So, leaving the clippings on your lawn actually helps fertilize.

For a more general tip, Richard suggested:

• Don't believe everything you hear or read (this article excluded, of course). Be skeptical of those selling you stuff. If it sounds too good to be true, it probably is. If you are not sure, call Richard at 515-294-3108. (Sorry, Richard!)

Whew! This is a good list to start off that novice gardener. But no list is complete, if we forgot anything you think is important - send me an email at chaynes@iastate.edu . I hope to add a part three with your suggestions later in the year. Be sure to include your name and hometown.

See also Garden Don'ts, Part I .

Figure 1. Strawberry plants.

Figure 2. Uncovering strawberry bed.

This article originally appeared in the 4/20/2005 issue.