Get your soil right. Prepare you soil with plenty of garden compost and well rotted manure (I mean composted green material here, not a bag of peat) to give the new seedlings plenty of nutrients. If you read my posts you'll be sick hearing 'it's all about about the soil' but there's no getting around the fact. If you build a good quality soil with plenty of organic material you will suddenly find you have the greenest fingers around. That's it, there's no mysterious secret.
If you don't have garden compost I recommend a mix of envirogrind soil improver and Lady Muck composted manure which will help build your soil structure for this year and years to come. Apply at a rate of approx 1 large standard household bucket per square meter. N.B. If you are sowing carrots or parsnips in the ground you're preparing leave out the manure and add at the end of the season.
Plan your garden. When planning your garden you need to take crop rotation into account to help reduce the build of disease and to prevent nutrient depletion in your soil. Growing the same plant in the same spot year after year is asking for trouble as the pests that attack the particular vegetable increase in numbers making it difficult and sometimes impossible to grow that crop in your garden again. Nutrient depletion happens when a certain crop uses a certain nutrient which is used up by growing in the same spot year after year.
The process of moving crops around to avoid these problems is known as crop rotation. It's simple really once you get hang of it and is another key element of a successful home vegetable garden. You can read about crop rotation in more detail by reading our crop rotation article here. You can also have a look at our excellent crop rotation video with Klaus Laitenberger if you fancy a rest from reading.
Planting depths for different vegetable seedlings. This is quite a general guide which covers most of the well know garden vegetables. I include the little illustration we send out with all our seedling packs below to show our recommended planting depth.
Up to the first set of leaves. As you can see in the first column the plants are planted up to the first set of leaves. This is very handy if you have a seedling that is a little leggy as you can bury a good proportion of the stem in the soil. This is worth remembering as if seedlings in the first group get a bit leggy in the greenhouse they can be rectified when planting out.
The plants will produce roots from the buried stem which in some cases, tomatoes for example, will improve the root system of the plant. Have a look at the tomato seedling in the picture where you can see the portion of the stem to be planted below my finger and thumb.
Soil level. Plants in the second column have stems which are likely to rot if covered up. Kohl Rabi and beetroot are the ones you are likely to get caught out on as you would expect to plant them deeper. Both of these plants form their bulbous root or stem above ground and shouldn't be covered up. Plant the seedlings in this group with the top of the compost in the plug level with the surrounding soil.
Above Soil Level. Lettuce seedling stems can rot very easily so it can be helpful to plant the compost plug slightly proud of the surrounding soil level to keep it away from the moist ground below.
Can we get on with planting them now? Alright. Rake out and remove large stones or lumps of soil from your intended planting are. Make a hole roughly the size of the seedling plug you wish to plant with a hand trowel or dibber (A dibber is a tool for making planting holes, see our oak dibber here). If the soil is very dry water achieve a good damp consistency. I like to sprinkle a small handful of seamungus seaweed and poultry manure pellets in the soil around the planting hole to give the new seedling a boost and to slow release nutrients for about 3 months.
Remove the seedling from the module or plant tray by gently squeezing around the plant to loosen the roots. The seedling should come out easily bit can be helped by pushing a pen up through the base of the module to release it. You can gently tease the roots out at this stage if they have formed a tight mass at the base of the plug.
Place the seedling in the planting hole and firm the soil in around the plant to remove any air pockets. This part is worth noting as most people press downward around the seedling which compacts the top of the soil rather than firming in around the plant. The motion required is more pushing the soil around the plant like tucking the duvet around yourself on a cold night. Those of you with small children will be very familiar with the action I suspect.
Water your seedlings well after planting. Keep the soil moist and don't let it dry out for the next week or two when the plants are settling in. Don't be alarmed if there is very little growth for the first week as it takes time for the plant to adjust to it's new surroundings. All the energy is going into the root department to build a water and nutrient supply to make sure the plant survives.
Protect your plants The majority of seedlings will be planted in late April - early May when there may still be a risk of frost about. Keep a roll of horticultural fleece handy, it's the best investment you'll ever make. It's relatively cheap but will protect tender plants from a mild frost which would otherwise wipe them out. Remember the new shoots of potato plants which will be starting to come up soon are also frost tender and may need protection.
Fleece is a very light material which will insulate seedlings from temperatures down to -3 or -4 degrees. Simply lay the fleece over the plants you want to protect and anchor the edges with some large stones. The material is so light that it wont damage the growing plants but is best pulled reasonably tight to stop it flapping in the wind. Fleece allows light and water to penetrate so can also be left on top of seedlings for a few days if required.
Keep an eye our for slugs and use a slug beer trap if you think you have a problem. A night time trip out to the vegetable garden with a torch can be quite an eye opener and will give you a good idea of slug populations.