Potted seedling
You’ve planted some seeds and now you have little plant pals growing bigger by the day.!

Depending on how you sowed your seeds, you’ll need to take different approaches to transplanting them into bigger containers to continue their growth and establish their roots further after germinating.

Pricking out is the method used when your seeds were sown close together and this needs to be done when you see the ‘true leaves’ grow – this is the second set of leaves after the 'seed leaf' and they are strong enough for you to work with.

Potting on is a similar process but could be the next stage after pricking out. If you planted one seed per seed tray compartment though, this is the process you’ll likely want to follow. This may be slightly later than the pricking out process as your plant has had more space to grow and is perhaps more established.

You can find the step-by-step for both methods below. We’re using tomatoes in this guide but some plants like beans may need deeper planters to continue their growth inside before going out after the last frost has happened, usually around mid-May.

Different plants need to be transferred to different sized containers and the instructions from seed packets or the internet would help you make the right decisions. You would use either a modular tray or a 9cm pot for seedlings to go into. The general rule is larger seedlings to the pot and smaller to the modular tray.

The reason we don't go straight into large pots from seed trays is to reduce the build of bacteria in wet soil, reduce root rot and your plants dying. Sourcing a variety of pot sizes is therefore a good plan!

Seed sowing in trays

This is a simple summary of how to sow seeds so that you can grow herbs, veg and flowers at home.

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  • Good distraction from other thoughts particularly negative ones as the mind will be occupied by the concentration required to do the task.
  • Practices our fine motor movements and works our sensation and delicate handling skills
  • Involves us in nurturing tender plants
  • Provides great satisfaction to see new tender plants thrive, again connected with the innate desire to nurture and care
  • Can provide us with an abundance of plants, more than we need, to share with neighbours and provide us with an opportunity to support others
2 seedlings
  • The delicacy required can be difficult for younger children, but they can fill the pots or trays ready for the seedlings. Older children may be able to participate in the full process but may find the repetition too much.
  • Children of all ages could wash the pots ready
  • Children could be the ones to water, this is where a homemade watering bottle can be even better than a heavy watering can - just be very gentle and don't overwater!
  • Get children to measure the growth of plants as they establish in their larger growing environment, seedlings usually have a growth spurt after a few days of reestablishing their roots and gaining anchorage. They could either make a graph or take photographs that can be stitched together to make cool time-lapsed movies.
  • Make sure you do this on a tabletop or stood next to a bench that leaves your back neutral and not bent.
  • If you have used modular trays to begin with you can squeeze the soil within each module and take out from the base. This avoids carrying seedlings which can be difficult and risky
  • A cutlery fork can also be a good tool to use if holding seedlings carefully is difficult, use the fork to lift each seedling from underneath and this can help minimise the risks of damaging seedlings
  • Concentrate on the strongest seedlings usually you will have more plants germinate than you needed and so some loss at this stage is fine
  • As an activity it involves a lot of concentration and so take your time, try not to leave seedlings with loosened soil but you could do this over a day or 2

Step 1: Equipment

If you’re moving from a small seed tray with no compartments and lots of small seedlings, you’ll likely be upgrading the plants to a modular tray. Get your modular seed tray to hand and fill each compartment almost to the top with compost for potting and press it down gently to make it firm.

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Step 2: Preparing the tray

Get your watering can and water the compost a little to moisten it and make a hole using your fingers, or if you have one, a dibber. This is a tool for helping you make holes for planting but you can also use a pencil. The hole you make should be big enough, importantly deep enough to fit the seedling that’s moving in, along with its roots. Repeat for each tray compartment.

Step 3: Transplanting the seedlings

You’re ready to move the plants across so gently hold one by its leaves (not the stem or roots as they are more vulnerable) and use your dibber or pencil to start to move the compost a few centimetres away and ease out the entire plant - be careful to keep the roots intact as much as you can and lean them on the dibber to take the pressure off the leaves.

If a seedling is very close to another plant, their roots might be tangled together so just pull these gently apart before moving them over to the new tray.

Note: If you have a lot of seedlings, you’ll want to choose the ones that have the best chance going forward so look for the largest and strongest. Some of the smaller and weaker ones might not make it!

Seedling

Step 4: Planting

Place the seedling carefully into the hole and press the compost around the plant with the dibber so it’s firm enough to hold up the seedling.

Step 5: Water

Making sure you have a rose on the watering can (if you don’t, check out how to make one or water around the tray so it can be soaked up), give the plants a drink and put them in a good spot for some warmth and sunlight!

Come back to the next bit of this article when your plants have established further and they need to be transplanted again into pots.

Your seedlings have got their own space but they’re ready for more – some faster growing plants like courgettes and tomatoes may need to go through this process a couple of times before their final container!

Step 1: Equipment

Find your pots that you want to move the seedlings into – if you’re tight for space inside, you might want to upgrade them to a small pot and pot them on once again before they go outside. Or you can transplant them straight into the bigger pots that they’ll stay in.

Note: Depending on what you’re growing, you can check what size container they need with a quick internet search. Tomatoes for instance, can be most happy in a grow bag rather than a pot when they are ready to bear fruit. If they are staying indoors or in a small yard, finding a tall, slim container might be a good solution.

Step 2: Preparing the pots

Fill your pots with compost, almost to the top and firm a little. Get your watering can and water the compost a little to moisten it and make a hole using your fingers, or if you have one, a dibber. This is a tool for helping you make holes for planting, but you can also use a pencil if you don’t have one. The hole you make should be big enough, importantly deep enough to fit the seedling that’s moving in, along with its roots. Repeat for each pot

Composted pots

Step 3: Transplanting the seedlings

You’re ready to move the plants across so gently squeeze the tray compartment to free up the plant with the soil and roots all staying intact. You can help get the plant out by using the dibber to push through the hole in the bottom of the container if there is one.

Hold the plant by the soil/root block and the leaves if necessary but not by the stem.

Note: If you have a lot of seedlings, you’ll want to choose the ones that have the best chance going forward so look for the largest and strongest. Some of the smaller and weaker ones might not make it!

Place seedling in pot 2

Step 4: Planting

Place the seedling carefully into the hole and gently press the compost around the plant with the dibber so it’s firm enough to hold it up the seedling.

Step 5: Water

Making sure you have a rose on the watering can (if you don’t, check out how to make one or water around the tray so it can be soaked up), give the plants a drink and put them in a good spot for some warmth and sunlight!

Repeat with a larger pot

You may need to pot up your plants as they grow into larger pots a few times.

Going outside

Check the seed packet for information about when your plants are ready to go outside and whether they need to be ‘hardened off’ - going outside in stages to adapt to the change in climate. It helps toughen them for what they’ll face outside the comfort of your home!

If you don’t have seed trays, you can reuse plastic food trays that some of your fruit and veg come in and similarly for pots, you can make some by reusing things like yoghurt pots and adding some holes into the bottom for drainage (make the holes by pushing though the bottom of the pot from the inside this will create a hole water can drain through - many plastic pots have either very flat or raised at the edge bottoms and this stops water escaping).

If you’re low on compost, try mixing it with some soil from the garden (if you have one) to make it go further.

The HTA offers useful information about where you can get plants locally to you at the moment.

Share your progress with us!

We'd love to see what you're growing and where and if you're getting creative with the space you've got. Share your photos with us on Facebook, Twitter or Instagram using #ThriveGardeningClub

Using nature to relax

Take the time to look at the seedlings and their various elements and also what you’ve accomplished so far by getting them to this stage. You are also another step closer to planting out and so go outside and look again at where you imagined planting them, is it still the right place?

A wonderful part of gardening is the evolution of everything, plants across the seasons, the garden across the years and our thoughts and decisions about where to plant evolve similarly. Imagine how the plants will live and look alongside their plant neighbours.

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Rebecca H potting up Charlie Garner 2019 3