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Beetroot seedlings aren’t always easy to start in module trays – either indoors or in a greenhouse. They’re a bit fussy, and you could run into all sorts of problems tending to these delicate little plants. One annoying issue that occurs right after germination is getting leggy beetroot seedlings.
The main factors that can cause leggy beetroot seedlings are light – not enough of it or the wrong kind of it, too much heat, or excess nitrogen in the soil mix. When seedlings fall over, it’s either because they can’t support themselves, they’re underwatered, or suffer from damping off.
From my own experience, it seems like beets have trouble with legginess compared to other, more forgiving seedlings. Gardening is a process of trial and error, so if you’ve grown some leggy beetroot seedlings this season, and if some of those feeble plants are falling over, check the following tips to see if you got anything wrong:
Reasons Beet Seedlings Get Leggy:
Leggy seedlings have tall, thin, spindly stems that don’t look like they have the power to support the plant for much longer. Oftentimes, the stems grow into a U-shape as the seedling topples over and then tries to reach the light again.
1. Your beets aren’t getting enough light.
If you’ve started your beets on a windowsill, it’s possible that they simply don’t get enough hours of sunshine and little direct sunshine. When we start seeds on a windowsill, the sun comes down at an angle, causing the emerging seedlings to lean toward the window, searching for more light.
Beets only need the indoor heat to germinate, so don’t be afraid to move them outdoors in a cold frame or a greenhouse right after germination, as these plants are frost tolerant and handle the cold well.
When grown under grow lights, beets need to receive 14 to 16 hours of light every day, and depending on your grow lights’ intensity, they should be placed quite close underneath.
Another possible issue with grow lights is getting the wrong red light to blue light ratio. Blue light makes seedlings stockier and encourages shorter stems. However, keep in mind that seedlings started indoors will always tend to be a bit leggier than those that sprout outside. There’s no perfect substitute for the sun.
2. Beet seedlings are getting too much heat.
Another cause for leggy beetroot seedlings could be too much heat. Beetroot is a cold-loving vegetable that is stressed by too much heat, and the same is true for beetroot seedlings.
Beets typically germinate at 77°F (25°C) but thrive in cooler temperatures of 60°F (15°C) during the day and 50°F (10°C) during the night. An extended period of temperatures below 50°F (10°C) can cause them to bolt in early summer, but they hate too much heat just as much.
I kept my seedlings in a very warm growing room in an attempt to make my peppers and eggplants germinate faster. However, I didn’t realize that all this heat could be hurting my other cold-hardy seedlings.
Too much heat can cause rapid growth in beets, as their stems shoot up faster than normal. This can be true for other cold-loving plants as well. Swedes are particularly susceptible to growing long, leggy, although surprisingly sturdy stems as well:
Different seedlings have different needs, and with beetroot, you never know how they’re going to react to the indoor environment you’ve set up for them.
You can fix this issue by lowering the temperature, and if you have a shelf system with your grow lights, move them on the lowest shelf, where it’s cooler, or the farthest away from the heat source.
3. Your soil mix may contain too much ammoniacal nitrogen.
Nitrates are related to short, compact growth in seedlings. Ammoniacal nitrogen, however, seems to be related to leggy seedlings. Some store-bought fertilizers aimed at farming may contain high amounts of urea that turn into ammoniacal nitrogen.
Furthermore, a hot environment can lead to a faster breakdown of nitrogen compounds and increased plant metabolism. All these factors put together can determine legginess in certain susceptible vegetables.
Always check the label on your growing medium for added substances, and choose a potting mix that’s free of additives, preferably peat-free as well. You can start your seedlings in compost from a reputable source or in a sterile mix, in which case they will need regular feeding.
Choose a hydroponic fertilizer that’s specifically designed to contain the perfect nutrient ratio for seedlings, but don’t overdo it. Beets don’t need much fertilizing at this stage.
4. You’re not watering your seedlings consistently.
The stress of underwatering can cause beetroot seedlings to stretch. Their stems will look thin and fragile. Eventually, when you forget to water them again, they’ll become weak and fall over.
Whenever leggy seedlings fall over, you should check to see if you’ve watered them enough because, with good watering, they may recover.
When plants fall over, I like to carefully remove a couple of beetroot seedlings and inspect their stems and root systems. If their roots look brown and their stems are pinched at the base, the culprit is usually damping-off disease.
Damping-off is a fungal disease that typically occurs in cold and damp conditions. If you find that damping off is to blame for your collapsed seedlings, remove the affected ones immediately.
However, if your beets are leggy and underwatered, there’s still hope for them.
5. You may have too many beetroot seedlings in one cell.
Although beets like to grow in clumps, if you’re growing beetroot seedlings underneath growing lights, they might get a little too competitive for the light, which could result in leggy seedlings.
I usually grow beets following the multi-sowing method, in clumps of four, but oftentimes, when I sow them, I either drop too many seeds, or multiple seedlings can emerge from just one seed.
If your clumps contain more than four plants per cell, thin them as early as possible by pinching the seedlings at the base.
Leggy Beetroot Seedlings Solutions:
You’ve ended up with leggy beetroot seedlings – now what? Do you have to start all over again? Not so fast. There are still plenty of things you could try to help these leggy beets recover.
Prick them out and plant them deeper.
You may have heard that root crops hate transplanting, and that’s partially true but not necessarily true for beetroot. Root vegetables that form a long taproot, like carrots, shouldn’t be started in modules because you risk getting twisted, forked roots.
Beets are surprisingly resilient, and even though they don’t enjoy being transplanted, they will quickly recover. That’s why planting young seedlings deeper into a new module is perfectly feasible.
Prick out the leggy seedlings, separate them carefully and twist the root and stem delicately into a new module so that most of the stem is covered by soil. The most important thing is not damaging the stem.
When we plant beetroot seedlings in the garden, we plant them deeply – up to their first leaves – so you can skip this pricking step entirely if you consider that your beetroot seedlings can still support themselves until it’s time to plant them out.
On that note, no need to wait for a full month to transplant seedlings outside – I’ve planted beetroot seedlings as young as two weeks old.
Be more mindful when caring for them.
If you’re planning on keeping your beetroot seedlings alive instead of starting over, you should be more intentional with caring for them.
Move them closer to the grow lights by placing a box underneath them or lowering the lights on top of them.
Water them from underneath so that you don’t encourage mold formation or damping off, and don’t go too long between waterings.
Feed the beet seedlings with a hydroponic fertilizer that doesn’t contain urea, or don’t feed them at all if you’ve started them in compost – they have all the nutrients they need.
Run your hands through your seedlings or install a fan to simulate wind so that their stems become thicker and stronger.
Always have another batch of seedlings ready.
The only serious reason for ditching your seedlings entirely is damping-off disease. But even if that happens – and it will most likely happen to you at one point or another – you can always start over.
If you start beetroot seedlings a couple of weeks later, they will surely catch up. Healthy seedlings always grow faster and better than leggy, sickly seedlings.
Beetroot seedlings do well when sown in succession – you can plant out several batches from mid-spring to early summer, and you will get a staggered beetroot harvest all year long.
For this reason, always have an extra tray of beetroot seedlings ready – worst-case scenario, you’ll have plenty of plants to give to friends and family.