Gardening > Trouble with Seedlings

Trouble with Seedlings


One of the most exciting moments in gardening is when the first flush of green from germinating seeds appears above the soil. If things start to go wrong at this stage it can cause much disappointment and frustration for the gardener.

Sometimes seedlings are found lying on top of the soil. This can be due to the seeds being sown too shallowly. Always study the instructions for each seed being sown – some need to be sown more deeply than others.

Another cause of uprooted seedlings can of course be animals. Cats and dogs will scrabble up small plants. Make a close “pallisade” around the seeded area with strong sticks or build a moveable, enclosed frame from wood and chicken wire to put over any vulnerable seedlings. If cloches are used make sure the have ends as cats will get into even the smallest cloche to sun themselves.

Wireworms, leatherjackets and cutworms can sever the base of a seedling stem in two attacking either at soil level or just below ground.

Small, regular “peppered” holes in the leaves of seedlings are often caused by flea beetles. In the vegetable plot they mostly attack cabbage, turnip and lettuce seedlings but are happy to have a go at just about anything. 

If you have lots of ants in your garden be aware that although they do not attack seedlings they do steal seeds. They can also cause seedlings to wilt and die because they loosen the soil and disturb the young plants.

Slugs and snails will of course decimate a row of seedlings in one night. There are now excellent, organic slug pellets on the market which really are worth a try if slugs and snails are a problem in your garden.

If the leaves of your seedlings have been nibbled around the edges leaving a distinctive, scalloped effect this is probably the work of pea and bean weevils.

Sometimes seedlings fail to appear. If the soil is just as you left it then the problem is likely to be the quality of the seed (always store seeds in a cool, dry place) or the seeds being sown too deeply – again read up on the seeds you intend to sow for a guide to sowing and general spacing.

If there is no germination but the surrounding soil has been disturbed suspect birds, mice, cats, dogs or ants.

When seeds are sown too thickly the seedlings can be spindly and weak (they will fall over very easily). They need to be properly thinned out as soon as they are large enough to handle. It is always better to sow sparingly. Modern seeds usually have reliable germination rates so there is no need to overcompensate for possible failures by sowing too generously.

Another cause of spindly seedlings can be lack of light. If you are starting off your seedlings indoors put them in a really light windowsill or porch and if you have used a paper or glass cover on the seed box to encourage germination make sure it is removed when the seedlings start to come through.

If the seeds have come up but the seedlings don't seem to be growing it could be that the soil is too cold. When sowing outside early in the year it is often best to use cloches. Over-dry soil can also hold seedlings back so water lightly if necessary. Sometimes seedlings that have been brought on indoors and then planted out do not do very well. This can be because they have not been hardened off properly. Before planting out seedlings need to be gradually exposed to the elements by putting them outside in their pots or trays for a few hours and then being brought in again especially overnight.

Sometimes pests can make it impossible to sow directly into the ground. This can happen in a newly cultivated patch. If this is the case sow individual seeds in peat pots, bring them on indoors or in the greenhouse, harden them off and let the vegetables grow quite large (2-3 inches). Lastly plant them out pots and all in the vegetable plot in neat rows. The larger and healthier the plant the less likely it is to succumb to attack from pests and diseases. Meanwhile you should concentrate on improving the soil and working out strategies to ward off pests.

It is well worth reading up about every vegetable you intend to grow. Concerns about depth of seed sowing, spaces between each seed and each row may seem over-fussy but attention to detail pays off. Seeds sown at the correct depth in a well-dug, pest-free plot, each seed given plenty of space and light will pay huge dividends in the size and quality of the crop produced.