There are several reasons for growing seed into young seedlings and then planting them out in the garden. In some gardens, seedlings of a wide range of plants are just too vulnerable to slugs and snails when they are germinating into tiny shoots in garden soil - so growing them in a protected container and planting them when they are about the size of your forefinger means they’ll stand more chance of resisting an overnight nibble that might have been the end of them when they were smaller. At times of the year when the weather is wild and wet - and soil can be deluged with rain – seeds can literally be washed away and shoots swamped - whereas seedlings can stand a better chance of getting established thanks to their size. In late winter, seeds of summer crops – like tomatoes, beans, zucchini, capsicums and melons - are started off in greenhouses and on warm windowsills so they are ready for the garden as healthy seedlings in early spring when weather conditions are warm.
Seeds sown in pots or punnets develop fledgling root systems as shoots grow into plants with several pairs of leaves. At this stage seedlings are usually ready for planting. When you have grown seedlings for your garden and they are ready to go into the ground there are a few things that can help to make their start in the garden a good one.
When we plant seedlings there is a risk that they may suffer from what is called ‘transplant shock’. Transplant shock is caused by delicate seedlings suffering stress and damage as they are taken out of their container and planted into the garden. Roots and stems can be crushed and, as a result, plants can grow stunted, with reduced yields and increased vulnerability to pests and disease. Signs of ‘transplant shock’ are curling or wilting leaves that become pale and discolored, drooping stems and plants collapsing altogether. Avoid transplant shock by following these easy guidelines:
Equipment: Prepared planting area/container, seedling, spade or trowel, watering can, label
Seedlings grown in greenhouses, cold frames or on a windowsill are accustomed to comfortable, stable conditions and should be planted out on a mild day – ideally when no frost, gales, torrential rain or other harsh weather is forecast.
Prepare the planting area well. Ensure soil or planting medium is right for the plants – for instance enriching for hungry seedlings or improving drainage for those that like it hot and dry.
Soak seedlings with water before they are lifted from their pot or punnet.
Handle seedlings as little as possible during the planting process, have your hole ready so you can pop them in straight away.
Make your hole the right depth so that seedling soil will be at the same level as garden soil.
If seedlings are in small pots or punnets, push gently upwards from underneath – rather than pulling them as this can cause damage. Handle seedlings by cupping them in the palm of your hand and only lift them by their root ball.
If seedling is in a larger pot, place flat hand across compost on either side of seedling stem. Turn pot upside down and tap on bottom, shaking gently till root-ball comes loose and plant can be cradled in one or two hands.
Place seedling in hole.
Back fill with garden soil or compost around your seedling, ensuring there are no voids or air pockets that can fill with water and deprive roots of oxygen.
Gently press soil down around your seedling to ensure good contact between seedling roots and garden soil or compost.
Water seedlings and surrounding soil immediately after planting.
Place a protective juice bottle or tunnel cloche over delicate seedlings – especially during harsh winter.
Mulch around seedlings to suppress weeds and retain soil moisture.
Label them if you need a reminder of what you have planted.