How to prevent leggy seedlings and help them recover
February-March is often a good time to start your first seedlings. Unfortunately, not everything always goes according to plan, especially when you're starting your permaculture vegetable garden. Some seedlings grow long, thin stems and may eventually topple over or break. This is known as becoming leggy. So how do you get top seedlings that will bring you pretty vegetables in a few weeks' time? Follow the guide!
Respect the sowing and planting periods
Avoid sowing too early simply to gain time. Courgettes grow quickly, so work backwards from a safe outdoor planting date in your region. Tomatoes need a longer lead time, but mid-March is only a regional example, not a universal deadline. Check the variety, available light and whether you have frost-free growing space.
Set up your vegetable garden and region in Permapotes to see a calendar for your chosen crops and climate. You can print the annual overview or export your calendar and import it into a compatible calendar application, such as Outlook.
A good ratio of light to heat!
Too little light in relation to warmth is a major reason why seedlings become leggy. A suitable balance helps them grow sturdier stems.
If you want to have aubergines or peppers in your vegetable garden, you very often need to get started very early. Plants of these two varieties grow very slowly, which means we often have to start their seedlings around February. If they are placed inside your home, which is highly recommended as these two varieties fear frost, the ambient temperature of around 19-20°C is far too high compared to the natural light at this time of year, even if you place them in front of a window. Your seedlings will then stretch towards the light to which they naturally turn because it is necessary for their growth. Of course, you might be tempted to counter this problem by placing artificial lighting above your seedlings, but favour natural light as much as possible ;-)
Of course, legginess doesn't just affect aubergines or peppers. Practically all seedlings started before April or insufficiently exposed to light can become leggy... After April, you can generally take your seedlings outside when you can, keeping an eye on temperatures to avoid exposing frost-sensitive vegetables such as tomatoes, squash or courgettes or aubergines. You can, for example, bring them into your house overnight to minimise the risks... and take them out again the next day, but this requires patience. For frost-tolerant varieties, I personally move the seedlings into an unheated greenhouse as early as April.
My solution for preventing my seedlings from becoming leggy!
After 4 years of vegetable gardening under my belt, I've finally managed to find the right technique for 100% success with my seedlings. For my part, I opted for a mini greenhouse placed upstairs in front of a south-facing window. Here's what my setup looks like.
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Why not a simple shelf?
The advantage of a mini balcony greenhouse is its mesh bottom, which allows light to pass between the different levels. With a conventional rack, the bottom of each tier is full, which reduces the amount of light, a very important criterion for starting our seedlings when the days are still short. You're going to tell me that with all your seedlings, the shelves will soon be full. I'd say no, not just yet! Only a few seedlings can be sown when the days are still short. So it will take some time for everything to fill up. Another advantage of this type of mini-greenhouse is that it saves space, as you can store a large number of seed trays in a narrow space. I paid around forty euros for my mini-greenhouse on this site two years ago, but you can now find them just about everywhere, in garden centres and elsewhere.
A few more practical tips: be careful not to create shadow play with your labels and make sure that the potting soil in your seedling trays or pots comes within 5 mm of the rim... again, to prevent your seedlings from stretching too far to stick out of the pot. -
Why a south-facing window?
Well, to get maximum light of course! =) If you place your seedlings in front of a north-facing window, they are more likely to become leggy! To get as much light as possible, try to find a spot that faces as far south as possible, or even south-east or south-west. If this really isn't possible (east or west facing), then you'll need to keep the room fairly cool, around 12-15° maximum, but your seedlings will take longer to grow. -
Why upstairs?
On the ground floor, the ambient temperature is generally 19-20°. Until mid-March, this temperature is too high in relation to natural light, which risks causing seedlings to become leggy. Upstairs, on the other hand, where the bedrooms are located, the heating only comes on if the temperature falls below 15°. This cooler temperature has the advantage of providing a better light-to-heat ratio for my seedlings, and minimises the risks.
I'd also like to take this opportunity to talk about watering: be careful not to overwater your seedlings... and be careful that the potting soil isn't too dry. Once the seeds have been sown in your pots or seed trays, you can, for example, soak them in a container filled with water. The water will then rise by capillary action into the soil and once the soil is sufficiently moist, all you have to do is place your seed trays in your little balcony greenhouse. For watering, I personally rely on the weight of my seedling trays, and water accordingly, either with a spray bottle or small sprayer, or by placing a tray containing a little water on the bottom.
How to rescue leggy seedlings
Some leggy seedlings can be rescued. Tomatoes can form new roots along a buried stem and may be potted on more deeply. This is not suitable for every crop: avoid burying the growing point of lettuce or automatically planting cucurbits deeply. Improve light and growing conditions as well, otherwise the new growth will remain weak.
So how do you achieve this intermediate transplant? Well, it's not very complicated:
- Prepare a small pot filled with potting soil to within 5mm of the rim and immerse it in a tub of water for a few minutes.
- Use a pencil or small stick to dig up your seedling, being careful not to injure the stem. Above all, don't pull the little seedling by the stem, which could break it.
- For a tomato seedling, make a hole in the new pot, carefully lower the roots into it and cover more of the stem if needed, keeping the leaves above the compost. Do not apply this planting depth automatically to other crops.
- Lightly pack the soil around the stem to close the small hole.
Is it really too late, and your seedlings are beyond repair?
In this case, you'll unfortunately have to throw them into the compost... and start all over again. If the season is already well advanced, you can always buy vegetable seedlings to transplant into your vegetable garden directly from garden centres, or even better: take part in exchange markets. Don't hesitate to look on Facebook for initiatives of this kind in your area. It's a great way to meet other gardeners, share tips, and swap seeds and plants between enthusiasts!
And what tips do you have?
I hope this article helps you to make your sowing more successful! If you have any other tips to recommend to Permapotes, don't hesitate to share them in the comments! =)
