15:31 - 10 May 2011
The secret to successful seeds and plants is learning to read your plants. Keeping them at their peak at every stage of growth is more than half the battle. By using the correct compost at all critical life stages helps your plants on their way, but you also need to respond to your plants on demand and in particular when they are ready to pot up or plant out.
How do you know?
As soon as you start to see fresh white roots poking through the base of your pots and modules it’s a sign that your plants are ready to move to the next stage of development. They need a good root system to grow strongly and if they have too much space to grow it can cause sour compost and root rot. This can mean you have to repot individual plants several times before they are planted out or planted into their final containers. Cutting corners by planting them into larger pots quickly or leaving them in each stage for longer doesn’t help. Leaving your plants in too small pots can hugely check their growth. Ideally you need to repot them while the new roots are searching for more growing space. So they need to be poking out of the module or pot and not crammed tight inside.
They also need to be growing strongly and looking healthy. If they’ve been grown in seed compost they may have already used up the nutrients in this special formulation, it is deliberately low in plant food to prevent scorching the delicate roots.
Preparing for potting
It’s a good idea to feed your plants a few days before potting them up. Water them first, you shouldn’t add a liquid feed to plants with dry roots, so let it soak in for a few hours and then feed with a dilute liquid feed. This will give your plants a boost before the shock of repotting and help to spurt them into growth exactly as you pot them up, so they hit the ground running. At this early stage of growth a general balanced liquid feed is a good choice but if they are starting to make flower buds then choose one high in potash (K) to boost flowering.
Keep the compost moist but not wet; if it is dry the roots can be torn as you tease the root ball from the pot.
Potting Up
Choose clean pots the next size up from the ones your plants are growing in. Deeper pots allow better root growth as the plants develop, but don’t be tempted with huge pots yet. Use a fresh batch of compost. A good quality multipurpose compost is fine if your plants are strong and healthy. It contains a generous amount of plant nutrients and will help support your plants through the next stage of growth. Fill the pots about a quarter full with fresh compost. Tip your plant out of its pot or module by supporting the top growth through your fingers and inverting the pot. Tap the pot if necessary, or squeeze the sides gently until the whole root ball falls out. Place the root ball on top of the compost in the pot and fill in around the root ball with fresh compost. Firm gently and water in with slightly tepid water.
Healthy plants will quickly romp away in the fresh compost and it may be just a week or two before they need potting up again. By pandering to your plants every whim you give them the very best possible start and ensure that they will develop into strong healthy productive plants. After all you’ve already invested time and money into every seed sown plant so don’t stop now, they will repay your efforts handsomely and you’ll soon to enjoying the flowers, fruit and vegetables of your labour.
