There are a number of benefits in growing a vegetable garden from seed you sowed yourself.
- Firstly, it's a lot cheaper than buying established seedlings!
- The variety of plants available from seed is much greater than the range of commercially available seedlings.
- A number of plants perform much better when grown from seeds sown direct.
- Some plants cannot be grown from transplanted seedlings and need to be sown direct
Sowing in punnets
There are few important points to remember when it comes to sowing seed. The seed needs to be kept moist, but not overly wet and never allowed to dry out. It must be in good contact with the soil. It must be sown in soil at the right temperature and to the right depth. It might seem that there are a lot of factors, but it really is quite easy.
Let's look at soil, important whether you're sowing into punnets or direct into the bed. This picture is of seed raising mix, available readily from retail outlets. it is specifically mixed to ensure that it is a fine mix, with both good water retention and drainage, with particles that ensure good soil contact.
Generally, we just reuse seedling punnets that we have kept from seedlings bought from the local nursery supplies. We do also have a few other options such as biodegradeable seedling "cells" and seedling trays etc. You can pretty much use anything, as long as it has adequate drainage. Another good option we've seen used is egg cartons. Once the seedling is established, the entire egg carton cell can be planted and the cardboard breaks down in the soil. If you're re-using any plastic container, ensure that it is clean, especially if previously used for planting. Wash it thoroughly in hot soapy water and rinse to ensure there is no bacteria that may affect your new germinating seeds.
Once you have a clean container, fill it around two thirds full of seed raising mix and water it to ensure it is wetted through, BEFORE planting the seeds. This will also settle the mix into the punnet and remove any airpockets. Follow the planting directions on the packet of seeds you have.
We usually place the seed on top of the wetted mix, then lightly cover it to the necessary depth, rather than pushing it down into the soil, but this depends on the size of the seeds.
Make sure you allow room for future growth, again this depends on the seeds being planted, larger plants and seed will need more room. As a general rule, we stick to a maximum of 6-8 seeds per punnet. When it comes to Cucurbits, such as Pumpkin, Squash, Zucchini, Cucumbers and Melons, only 3 per punnet.
Cover the seeds with a light dressing of more seed raising mix to the necessary depth and then very lightly water this. We use a hand pressure sprayer that just provides a gently spray/mist, otherwise you risk washing the seeds out of the soil. Label the punnet so you know what is in it and when it was planted, trust me, don't rely on your memory, you WILL forget.
The next important thing, is to keep the seeds at a fairly constant temperature. This can be done in a small greenhouse, under a glass frame or on a sunny window sill, but not in extreme heat. We use a heated tray that is temperature controlled, and cover the punnets with plastic covers, this helps keep the temperature right, minimises evaporation and keeps the humidity up as well.
On occasion, you'll encounter seed that has been pretreated with a chemical to help ensure it germinates, in the case above, Thiriam on corn seed. This is poisonous, so don't be tempted to use the seeds for anything other planting. There are other seeds that need to be treated in certain ways to ensure germination as well, but the natural processes that occur usually take care of this for you. They are pyramid shaped to encourage the roots to grow downward, giving them a better start when transplanted. We'll plant two successive crops of corn, these you see, then when these get a start, we'll fill the empty cells with the second planting.
For example, Beetroot seeds are small clusters of multiple seeds, coated in a corklike cover. Germination is drastically improved if the seeds are soaked in a glass of water for several hours before planting. Others such as Tomatoes needs to "ferment" somewhat before they can be planted. This would occur naturally in a rotting piece of fruit that had fallen to the ground in the "wild", the bacteria etc cleaning the seed ready for germination. Tomato seed purchased is all ready for planting, so you only need to look at this if saving your own seed.
Don't Love them to death
What does this mean? Well, usually, the most common causes of failure in seed germination is from too much or too little watering, and, sometimes, old seed. Bare in mind that even in fresh seed, not all will be viable. Some of the heirloom suppliers actually tell you what the expected germination rate should be..
In some instances, seeds such as beans, peas, corn and other cucurbits should only be watered once when planted, then not again until the shoots emerge. Too much watering causes these to rot in the soil. Obviously YOU need to judge the moisture of the soil and balance this. If it is warm and the shoots are not yet emerging AND the soil is starting to dry out, then a secondary light watering might be prudent.
In only a couple of days, the cucumber seeds above are already on the move! This year we're growing heirloom varieties of Cucumber, Lettuce, Corn, Pumpkin, Spinach, Capsicum and imported Italian varieties of tomato.
This term means sowing seed directly where the plants are going to grow, removing the need to transplant seedlings. This practice is best suited to root crops that do not like being disturbed as seedlings, but basically anything can be direct sown as long as the soil temperatures suit the needs of the seed. In cooler climate areas for example, some of the warm season crops such as capsicums, corn, melons etc, may not get enough growing time outside before temperatures fall too low again, so raising sees earlier in a greenhouse, gives you a headstart.
This is an example of direct broadcast sowing of carrot seed. Carrot seed is very fine and can be planted one of two ways. If in a dedicated pot like this, broadcasting the seeds across the surface and gently covering it produces this result. Alternately, you can plant in rows or "drills". An easy way is to mix the seeds with dry fine sand, then pour it out of a container with a small pouring hole in the top along your drill. This also helps to space out the fine seed more evenly. Cover the seed with somevery light friable soil, or better, seed raising mix and water gently. You will still need to "thin" the seedlings out once they emerge. (as the case here) This will prevent overcrowding and allow room for the plants to develop.