Everyone who has a hobby made mistakes while learning the skills needed to succeed. Usually over time, we make new mistakes as we try new methods. New gardeners make different mistakes than those with experience, but we all kill plants.
Dr. Doug Welsh, was the coordinator of the Texas state Master Gardeners program for 21 years. He is the co-author of Xeriscape Gardening: Water Conservation for the American Landscape and the author of Doug Welsh's Texas Garden Almanac and produces two weekly Texas gardening programs.
As the keynote speaker at the Texas Master Gardeners' Conference, Welsh detailed gardeners' top ten mistakes. Are these your top ten mistakes?
1. Overwatering - Twenty-five percent of water used by people in towns and cities is used for landscapes and gardens. Overwatering encourages shallow roots and stresses plants. His tip is to watch crape myrtle and hardy hibiscus shrubs for signs of needing water. When they wilt it is time to water. Water so the soil is wet several inches down, encouraging deep roots.
2. Overfertilizing - Too much fertilizer causes excessive growth and can burn plants.
Sixty to 70 percent of the plant marketplace is owned by the big box stores. They offer specific fertilizers for camelias, azaleas, etc. Gardeners do not need to buy four kinds of fertilizers. It’s just marketing. A product is never the answer to a gardening question.
Cultural practices and soil development are more important than fertilizers. For example, gardeners who collect grass clippings and leaves and compost them will have better soil and plants, improve the health of the environment and reduce the use of chemicals.
3. Misusing pesticides - There is more snake oil in the horticulture industry than in most. Be skeptical. Look for data that proves the value of the products you are considering adding to your garden.
Neem oil and Spinosad are the best products available that do not harm beneficial insects or birds. Use neem for soft biting insects such as mealy bugs and aphids and spinosad for hard biting ones (caterpillars, thrips and beetles). Chemical use can upset the balance of nature.
4. Improperly identifying a problem - Identify whether the problem is an insect, disease or environmental. Insects pierce, chew and suck on plant parts. Diseases are caused by fungi, viruses, bacteria and nematodes. Do not treat cultural problems such as water, light, nutrients or chemicals with a fungicide or pesticide.
5. Using plants that are unproductive and or poorly adapted to your area. For example sun tolerant coleus can take full sun in Michigan but not in the south.
6. Planting the right plant in the wrong place. If you have a small space, avoid planting an oak tree that will reach 60 feet high and 40-feet wide.
7. Failing to prepare the soil before planting. This is the worst mistake made by gardeners. Untreated soil is one percent organic matter and that is not enough to support healthy plants. In hotter climates, microorganisms break down organic matter quickly. Every time you plant a vegetable in the garden you have to add organic material such as composted manure, shredded pine bark or compost. Think like a plant. Eliminate weeds, add organics, till, aerate.
8. Failing to use mulch. This is the highest impact, lowest tech method. Mulch prevents soil disease splash, saves up to 25% water, keeps roots cool, reduces weeds. Mulch beds and containers with 2 to 4 inches of organics.
9. Planting at the wrong time. For example, one 40-degree night will permanently stunt the growth of a tomato plant.
10. Failing to think long term. Let your garden evolve slowly. Avoid shrubs and vines that need weekly pruning, daily watering or are disease prone.