It’s important to know what to look for when buying tomato seedlings. Healthy tomato seedlings will vary depending on the time of year, and it’s easy to fall into the trap of buying plants with tomatoes already on them but, should you buy tomato plants with fruit already ripening? Or is it best to buy smaller seedlings?

In this article, we’ll look at how to spot a healthy tomato seedling and the signs of a good tomato plant.

Is it better to buy tomato seedlings or tomato seeds?

You will invariably get healthier, stronger tomato plants as a result of growing tomatoes from seed, but there are often factors outside our control that mean growing tomatoes from seed just isn’t possible. 

Whether your seeds have damped off, you don’t have enough space to propagate and germinate seeds, or you’re just too busy to sow tomatoes from seed, buying tomato seedlings can save a lot of time, and get things back on track.

The biggest benefit of tomato seedlings is that they have already gone past that tricky germination stage, and now all you need to do is pop them in a grow bag and water for the next couple of months. If you’re starting a new garden, it can also be more cost-effective to grow tomatoes from seedlings bought at the garden centre as you don’t need to buy seed trays, pots, seed compost, perlite, etc.

When to buy tomato seedlings

The best time to buy tomato seedlings is late spring, when the ground is warm enough to plant them straight into the garden or greenhouse, the days are giving us over ten hours of sunlight, and the temperature is averaging around 10-15°C overnight.

In simple terms, for most of the Northern hemisphere, that means that the best time to buy tomato seedlings is May-June.

Beware though, that tomato seedlings bought from garden centres often look too good to be true. Tomato seedlings with fruit on them in May will finish fruiting in July and usually won’t ripen with anywhere enough flavour. By May or June, tomato seedlings should be around 1-2ft tall, with a few trusses starting to form. Below, we’ll look in detail at the signs of a healthy tomato seedling.

Choosing the right tomato plant

Choosing the right tomato plant is all about visual clues but, as well as picking a good plant, choosing the right variety is crucial.

Cordon or bush?

There are two main forms that all tomato plants can be grouped into; cordon and bush. 

Cordon, or indeterminate, tomatoes need much more care than bush tomatoes. Cordon tomatoes need training and pruning regularly to avoid them putting all their energy into leaves and height, with some varieties easily reaching 2m tall in a single season if left to their own devices.

For most gardens, bush tomatoes (or determinate) tomatoes have pre-determined heights, widths, and growing habits, which make them far easier to manage. Check the label when buying tomato seedlings to be sure which you are buying

For outdoor tomatoes, bush varieties are almost always the best choice, but for greenhouse crops, indeterminate tomatoes allow for more aeration, and harsher pruning and are much less likely to suffer blights.

Cherry, Plum, Salad or Beefsteak?

There are four types of tomato fruit you are likely to find in garden centres, and each has its own uses. Choose the best type of tomato for you, based on quality, flavour, and how hard they are to grow:

Type of tomatoUseCommon diseasesMaintenance level
CherrySalads / SaucesBlightLow
BeefsteakSandwiches / GrillingBlight & Blossom end rotHigh

Greenhouse or outdoor tomatoes?

In the next section we’ll look at how to spot health issues on tomato seedlings before you buy them, but one quick note first. Greenhouse tomatoes are often kept outdoors in garden centres, which can produce yellow, droopy leaves. This is simply a result of them being unhappy in their location rather than an indication of an unhealthy plant. Check the label, and if it’s a greenhouse tomato, it will probably spring back to life when you get it home, in a conservatory or under glass.

How to pick a healthy tomato plant

Choosing the best tomato seedlings is all about plant health. When you know what type of tomato you want, you’ve understood when to buy it, and you’ve got your garden ready, the final barrier standing in your way is the health of the plant you’re buying.

There are three things to check in every garden centre, DIY store, or supermarket before buying any tomato plant:

  • Foliage health
  • Root health
  • Pest damage

Foliage Health


Tomato plants with yellow leaves may be suffering from blight, but this can often be a sign of overwatering at this young stage, as their roots are sat in excess moisture. Check the soil in their pots. If it is excessively moist, and there are no spots on the leaves, this tomato may be suffering, but will likely recover quickly at home if watered properly.

Brown leaves on tomato plants are a sign of under-watering, particularly if the soil is dry, and the leaves are slightly curled and floppy. 


Assuming you are buying tomato seedlings before June, they should be around 1-2ft tall. Tomato plants that are taller are unlikely to fruit well and will need pruning back significantly when you get home. Aim for tomato pants with 1-2 trusses that are no taller than 2ft tall. 

Signs of blight/infection

Signs of blight include:

  • Papery yellow leaves with brown spots
  • Black dusty stems
  • Stems spring when touched
  • Black spots on leaves

Tomatoes can get blight at any stage in the season, and this is the first thing you should check for when buying any tomato. If there are signs of blight on a young tomato, don’t buy it, or any tomato near it, as you will spread blight to your own garden.

Crisp leaves

Crisp leaves on tomato plants are often caused by pests, but can also be a sign of sunburn. This isn’t necessarily a fault with the plant, and may just be the location in the garden centre. If the tomato plant is being stored indoors, or outdoors in full sun, check the variety. If it’s an outdoor tomato like Gardener’s Delight it may well just need some water and a little shade for a few days to recover.

Root health

While most chain stores are unlikely to let you check the roots of a tomato seedling, good garden centres will usually be happy to let you gently tip plants out of their containers to check the health of roots. Always keep in mind the old adage – you break it, you buy it! Be careful when checking roots in garden centres.

Tomatoes with black roots are unhappy, and probably suffering from root rot. Smell the root ball, if it smells infected, it probably is.

Pot bound tomatoes can be identified by large fleshy roots poking out of the base of a pot or wrapped around the root ball inside the container. While pot-bound tomatoes are about to wilt, they can be recovered. Simply tease their roots out before planting them to give them the best chance of survival.

Tomatoes with little or no roots are most commonly found in chain stores. The practice of growing tropical plans in tea-bag-like plugs that are then popped into the soil can restrict the roots of tomatoes, meaning they send out tiny fibrous roots, but their main roots never fully develop. If you gently tease the bag from around the roots and leave the tomato to root into the surrounding compost for a week or two it will recover, but this is usually a sign of a badly grown tomato.


Whiteflies, aphids and spider mites

Whiteflies and aphids can devastate tomato seedlings, covering their new shoots as they appear and completely preventing growth or photosynthesise by blocking leaves from unfurling or sucking the water from the stem. 

Always check plants from garden centres for aphids, particularly young vegetables like tomato seedlings.

Slug damage

Slugs are frustrating, but if you see slug damage on tomato seedlings check under the pot. 9 times out of ten, slugs are hiding in the grooves underneath tomato pots during the day, and crawl out to feast at night. 

If your tomato has a few bites, there’s no reason to worry, just make sure you remove any slugs from the pot before buying tomato seedlings. 


Tomatoes are such an addictive vegetable (fruit, we know) to grow that it’s incredibly hard to go a year without. If you’ve found yourself sitting in the garden in late spring, thinking it’s too late to grow tomatoes this year, don’t worry.

As long as you know what to look for when buying tomato seedlings you can’t go wrong. Finding a healthy tomato seedling pretty much guarantees a good crop. Just keep it well watered, well heated, and well cared for and you’ll have rich, ripe tomatoes in no time.

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