Seven Garden Gaffes to Avoid This Year

Left photo: Spruce trees planted too close to front of house are now blocking the entrance and views. Right photo: Volcano mulching is very bad for trees.
Left photo: Spruce trees planted too close to front of house are now blocking the entrance and views. Right photo: Volcano mulching is very bad for trees.

By Sarah Browning, Extension Educator in Lancaster County

What’s the difference between a new gardener and an experienced one? The experienced gardener has killed way more plants — or so the saying goes!

Even armed with a substantial amount of knowledge, gardening is still a highly trial-and-error venture. Sometimes that’s on purpose, as gardeners try new plants in their gardens. Sometimes it’s an accident, when a plant that should grow in a particular site just won’t, no matter what you do.

But it’s always good, when possible, to learn from generations-of-gardeners-past and not have to make every single mistake yourself. Here are seven gardening lessons to help you avoid a few common gardening missteps.

1. Underestimating How Big a Plant Will Get. It’s so hard to visualize how big — tall and wide — the small plant you put in the ground will eventually become. We’ve all seen houses completely covered up by evergreens planted way too close to the foundation with little understanding of how big the trees would eventually grow. No matter if it’s a shade tree, evergreen, shrub or perennial, this mistake is all too common.

Do some research before putting a plant in the ground and have a good understanding of how tall and wide it will get. Pay attention to suggested spacing and follow these recommendations as a minimum. Don’t worry about your neighbors teasing you for planting a tiny “stick” 20-30 feet from your house; they probably have to tunnel through junipers to get to their front door.

2. Pruning Off Flower Buds. This is often the answer to the question, “Why didn’t my forsythia/lilac/hydrangea/etc. bloom?” Spring and early summer blooming trees and shrubs form flower buds the previous fall. Winter or early spring pruning removes many of these flower buds, so wait until after these plants have bloomed to prune.

3. Killing Plants by Not Watering Enough. All newly installed plants, even drought-tolerant species, need supplemental watering until they are well-established. Perennials can develop enough roots to be considered established in 2 years, but woody shrubs and trees often take 3-4 years. Pay attention to how much (or little) precipitation your garden plants receive and check soil moisture with your index finger if plants are wilting. If the soil is dry, provide deep, infrequent irrigation.

4. Killing Plants by Watering Too Much. This is a common problem in landscapes with in-ground irrigation systems which are run too often, but also commonly affects plants in poorly drained locations, such as low spots where water collects and areas near the base of downspouts. Houseplants or plants in containers without drainage holes are also common victims to overwatering.

Improving soil drainage through aeration or building raised beds will alleviate the problems of poorly drained soil and low spots. Another strategy is to use plants in these locations which prefer high levels of soil moisture or are tolerant of wet roots.

Turf irrigation should not begin until the soil feels dry and the first signs of wilting symptoms are seen — a slight change in grass color to blue gray and leaves that do not spring back after foot traffic.

Cool season grasses, including Kentucky bluegrass and tall fescue, do not need irrigation in eastern Nebraska until dry conditions begin, usually in late June. Turning on a turf irrigation system in May and running it 2 or 3 times a week all summer is a recipe for trouble, including an unhealthy lawn and tree death.

5. Accidentally Killing Plants With Pesticide Applications. Using pesticides is tricky and even when using the correct product, plant damage can occur if the product is mixed too strong, plants are drought-stressed or the temperatures are too high when the application is made. But unfortunately, a simpler explanation is all too common for plant damage — the wrong product is used, often a result of not reading the label thoroughly or understanding the product being used.

One common example of “wrong product” is the use a non-selective herbicide in a lawn to kill weeds, then finding that product killed all the plants it was applied to. Always read product labels carefully to make sure you are using them correctly.

Another common occurrence is damage from residual product in a sprayer not cleaned thoroughly after use. The best practice to avoid this type of damage is to have several sprayers, each designated for a specific product or purpose. For example, have one sprayer for non-selective herbicides like glyphosate (RoundUp), another for broadleaf weed killers and a third sprayer for insecticides. Thoroughly cleaning the sprayer after each use is still recommended!

6. Volcano Mulching. This refers to a cone-shaped mulch mound piled around the base of trees and laying against the tree’s bark. Excessively deep volcano mulch provides an excellently protected habitat for voles, which commonly damage the bark of young trees in winter. Volcano mulching also holds moisture against the tree’s bark, promoting infection by bark rots, which may eventually lead to death of the tree.  

Mulch should be applied at a depth of 2–4 inches; 2-inches for perennials and 3 to 4-inches for woody plants. With fine organic mulches, such as compost or shredded leaves, maintain a 3-inch layer. For coarse materials, like wood chips, maintain a 4-inch layer. Mulch should be applied in a flat, wide layer — like a pancake — and kept back a few inches from the plant’s trunk, so it is not laying against the bark.

7. Planting Too Early. Spring fever is hard for gardeners to resist, but remember soil is still cold and the chance of normal spring frosts between now and late April is guaranteed. Make sure the soil is warm enough for vigorous plant growth before putting anything in the ground. You can check soil temperatures at or buy a soil thermometer and measure your own soil temps at a 4-inch depth.

If you are a beginning vegetable gardener or want to double-check the recommended times for planting vegetables, check out “The First Steps of Vegetable Gardening,” Don’t plant frost tender plants before the last average frost date unless you’re willing to protect them! For the Lincoln area, there is only a 10% chance of a spring freeze after April 29-May 12. Find the average last frost dates for your location at “Dates and Probabilities for the Last Spring Freeze,”

This column was inspired by 10 Gardening Gaffes to Avoid in the New Year, from the National Garden Bureau, author George Weigel.