Photo by Rachael Brugger High-nitrogen fertilizers are important for the growth of leafy greens, like Swiss chard.

There’s a lot to learn about gardening, but it’s a fun adventure and well worth the time and energy. Make the most of your gardening with these experienced gardeners’ tips to prevent and fix some common gardening mistakes.

Gardening Mistake No. 1: Starting Out Too Big
It’s difficult to resist those tempting photos of perfectly ripe vegetables and fruits in seed and nursery catalogs. It’s all too easy to order more vegetable varieties than your garden space and time will permit. Planting too large a garden is a mistake that can place too heavy a workload on a gardener and lead to frustration and burnout.

A better gardening strategy is to start small in the first year and plant only a few of your favorite veggies. This will allow you more gardening success and a greater feeling of accomplishment. In succeeding years, as practice builds your gardening skills, you can increase the size of your garden each planting season.

Gardening Mistake No. 2: Not Properly Preparing the Soil
Without good soil, no vegetable garden can thrive. Any preparation that the soil needs must be done before planting. Once those seeds begin to establish a root system, the soil cannot be disturbed without endangering the tender, young plants.

Prepare the soil as early in spring as you can work it without creating mud pies. Let the soil rest until the weather is warm enough to sprout seeds and support the growth of young plants. Then you can plant your vegetable garden and watch it spring to life.

Gardening Mistake No. 3: Ignoring Light Requirements
Vegetable plants need sunlight to grow properly and process soil and water nutrients. When choosing your garden spot, make sure that the area gets enough sun to grow the plants you want to put there. Some plants require more sun than others, and those light requirements must be honored when planting your garden.

Check planting recommendations on seed packets before you decide where to plant each seed variety. Some plants need full sun; other plants do well in partial shade. The directions on seed packets will tell you. Plan your vegetable garden before you plant, giving full-sun spots to veggies with the greatest sunlight requirements.

Gardening Mistake No. 4: Over- or Underfertilizing
Too much, too little or the wrong type or timing of fertilizer will not allow your garden plants to produce healthy, vigorous growth. For example, all plants require nitrogen, and high-nitrogen fertilizer will produce vigorous top growth—which is what you want for leafy green vegetables like chard, cabbage and lettuce. That same amount of nitrogen, however, will create such vigorous top growth that it can hold back ripening.

Excess nitrogen can have a similar effect on root vegetables. Robert Thomas of Tonasket, Wash., warns enthusiastic new gardeners: “Please, go easy on that wonderfully rich manure and homemade compost where you are going to plant your potatoes. Manure and compost are such rich sources of nitrogen that putting too much on a potato patch can cause excessive top growth and delay the development of the edible tubers.

Gardening Mistake No. 5: Over- or Underwatering
Plants need water to metabolize nutrients and grow, but different types of vegetable plants need different amounts of water. Too little water will cause plants to dry up and wilt. Once seriously wilted, most plants will not recover, even if watered, so do your best to keep your vegetable plants from wilting. Too much water can rot the root system, and only healthy roots can absorb nutrients from the soil and hold the plant upright. Once rot afflicts the root system, the plant is done for.

Most vegetable plants prefer a good, deep watering one to three times each week. If you water too shallowly, the roots will grow near the surface instead of downward to seek water.

“If you don’t water your vegetable garden deeply and thoroughly, you might end up with shallow roots that cannot tolerate any drought at all,” warns Rebekah James Pless of Spencer, N.C.

When you water your vegetable garden, ensure that the roots receive moisture. If you don’t know whether you’re watering deeply enough, check soil moisture by inserting the probe of a moisture gauge to the depth of the plant’s roots.

Gardening Mistake No. 6: Planting Too Deep or Too Shallow
In general, the larger the seed, the deeper it prefers to be planted. Seed packets offer information on the back about how deeply to plant the seeds. Pay attention to this information, because planting too deeply will cause seeds to fail to sprout or tire out the young seed sprout before it’s able to reach the surface and receive needed sunlight.

On the other hand, planting seeds at a too-shallow depth can cause the seed to dry out quickly and fail to sprout—or cause the young plant to dry out or fall over because of poor root growth. Some vegetable seeds, such as lettuce, actually need to be close enough to the soil surface that sunlight can touch them and trigger sprouting.

Gardening Mistake No. 7: Planting Bulbs Upside-down
Onions, garlic and other bulbs have a root-growing end and a stem-growing end. Make sure that you know which is which before you plant these seeds.

Planting bulbs wrong-end up will cause delayed growth as the root and top try to find the right direction to grow. This can use so much of the energy stored in the bulb that by the time the sprout reaches sunlight, the plant is weak and will fail to thrive. In most cases, the top of a bulb comes to more of a point than the bottom, so it’s not too difficult to tell which end should be up when planting.

Gardening Mistake No 8: Planting Too Closely—and Not Thinning
If you plant your seeds or transplants too closely, you’ll create too much competition for the nutrients in sunlight, soil and water. Seed packet instructions include advice on plant spacing, but it’s tempting to ignore it because seeds seem so tiny when you’re planting a patch of bare soil. It’s difficult to imagine how much space the plants that sprout from those seeds will need once they start to grow.

Not every seed planted will germinate and not every sprout will survive, so it’s OK to plant seeds closer than the spacing needed by mature vegetable plants. It’s important to thin the patch or row when plants are a few inches tall, removing enough of the seedlings to make room for the remaining plants to grow. Many vegetable plant thinnings are edible — young carrots and greens are tender and delicious—so enjoy your thinnings in an early-spring salad. Vegetable plant thinnings also can be left on the soil around remaining plants to serve as light mulch.

Gardening Mistake No. 9: Letting Weeds Grow Too Large
The best time to pull a weed is when it’s tiny and its root system is small. Pulling weeds at that stage of growth won’t disrupt the roots of your vegetable plants.

The longer you let a weed grow, the stronger a root system it will develop and the more nutrients it will steal from your vegetable plants. Keep weed growth to a minimum by mulching soil around your vegetable plants or disturbing the surface of the soil by regularly hoeing between your plants.

Gardening Mistake No. 10: Overmulching
Mulch is a good thing, but too much of a good thing usually isn’t. Mulching with organic matter—like straw, dry leaves or grass clippings—helps keep weeds from sprouting, retains moisture in the soil, keeps the root zone cool and provides nutrients for the plants as the mulch decays.

A light mulch is fine after planting, but don’t mulch too deeply or seed sprouts might not be able to push through into the sunlight. To retain soil moisture and discourage weeds, gently add more mulch as the plants grow. After mulching, draw the mulch back 1 inch or so from the stems of the young plants so it doesn’t create too much heat as it decomposes or trap dampness against the stem and cause rot.

Take special care when using green mulches like fresh grass clippings, as these materials produce heat while decomposing, which can harm the plant and even kill it. Green mulches are very rich in nitrogen, which they release as they decompose. This nitrogen boost will fuel top growth in vegetable plants, which you might not desire.

Don’t use grass hay as mulch. It often contains seeds of weeds that can spread rapidly and become very difficult to remove once they’ve established themselves in a vegetable garden. Wheat straw contains fewer weed seeds, so it is usually a safer mulch than hay.

A lot of gardening questions become common sense to a gardener after a few seasons of experience. There’s a lot to learn along the way, but you will learn how to avoid a bunch of common gardening mistakes.

Excerpt from Vegetable Gardens, part of the Popular Gardening Series, with permission from its publisher, BowTie, Inc. Purchase Vegetable Gardens here.