3 Common Garden Planning Mistakes (and How to Avoid Them)

, written by Jeremy Dore gb flag

Onion flowering

We can all learn from our mistakes and gain valuable experience in the process, but it’s much easier to learn from someone else’s! There are three very common mistakes that most gardeners will make at some point when planning a vegetable garden. Read on to learn what they are and how to avoid them.

1. Overcrowding

Even experienced gardeners will tell you that every now and again they succumb to the temptation to try to grow more in the space they have. Perhaps it’s because seed packets typically come with generous quantities of seeds, so it’s tempting to raise more plants than you actually need. When first planted it will seem as if they are growing perfectly well, so you may not notice the issue straight away – it’s only when the plants are approaching full size that the problems start, as each plant’s root system begins to compete with its neighbors for water and nutrients from the soil and the plants fail to mature properly, resulting in a disappointing harvest.

Close planting

To avoid this, make sure you grow your plants at the recommended spacing. The Garden Planner will automatically space plants along rows or in blocks, calculating how many will fit, and you can use the colored area around the plant to see how much space the roots require for good growth. If you have poor soil it’s a good idea to leave a little extra space, and if you’re using the Square Foot Gardening method, be sure to switch to SFG mode to see how many plants can fit in each square.

2. Ignoring Nature

Do you envisage your garden as a miniature farm, with big areas of beautifully growing crops? It may be wise to think again! There’s a reason why many farms growing huge fields of the same crop use pesticides – monocultures are easy for pests such as aphids to find and provide the perfect habitat for them to thrive in.


A little forward planning can ensure that Mother Nature is on your side. For example, it’s a good idea to mix in several different companion planting flowers to attract beneficial insects such as hoverflies so that, when the pests descend, these natural predators will keep them at bay. If pests strike early in your area, remember to include some early flowering companions or leave a few onions, garlic bulbs or carrots in the ground over winter to flower early and provide an excellent first source of nectar to attract nature’s defenders.

Scientific studies have shown that mixing up crop families (shown in our Garden Planner by the different colored backgrounds) helps to confuse flying insect pests, but for some crops it’s necessary to use further protective measures. For example, cabbage white butterflies lay their eggs under the leaves of cabbages and other brassicas, and when the caterpillars hatch they can decimate your crops in a few days. To prevent this many gardeners keep these crops together in one bed, covering them with fine netting to keep the butterflies off. Similarly, carrots are often covered with fine netting or fleece to prevent carrot fly.

3. Planting everything at the same time

The old adage ‘don’t put all your eggs in one basket’ is good advice for vegetable gardeners. Planting out all your tender crops at once can be disastrous if there’s a sudden late frost; similarly, transplanting pea seedlings only to have birds or slugs eat them is all too common.

The best method is to sow seeds in small batches, every two or three weeks. As well as ensuring you have backup options if disaster strikes, this has the added advantage of preventing gluts by spreading your harvest out over a longer period.

Garden Planner Plant List

The blue and green bars in the Garden Planner’s Plant List indicate the window of time during which you can make multiple sowings in your local area, and you’ll receive email reminders every two weeks. The Plant List also shows the number of plants you need for each vegetable, which can be a real time- and money-saver, helping you to raise just the right number of plants for the space you have.

There’s much more to successful gardening than just these three tips, but by avoiding these common mistakes you’ll save yourself some hard work and heartache and get your garden off to a great start!

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Show Comments


"Great video. I've been gardening for a long time but still seem to make at least some of these mistakes regularly. This year I will attend to these points. Thanks!"
Sandra Lindberg on Friday 3 January 2020
Hobart Crudd on Tuesday 1 February 2022

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