Growing Plants from Seed

Growing plants from seed can be very cheap and quite relaxing.  Not all plants can be grown from seed, but herbs, vegies and annual flowers are easy and have a high success rate.  Be patient though and plan ahead.

BEFORE SOWING SEEDS

• Select seed varieties to suit the seasons.  One of the fastest ways to fail is to try planting summer seeds in winter.  There is no arguing with Mother Nature, so a little research is always best.
• Seeds can be sown into pots, but seed trays are cheap and easy to buy and are probably easiest to get the seedlings out of once they have sprouted.

SEEDING IN TO TRAYS

• Fill a seed tray with at least a 5cm deep layer of seed-raising mix and give the tray a light tap on the bench.  Seed raising mix has no fertiliser in it, so its purpose is simply to allow the seed to germinate.  If a normal potting mix is used, it is possible that the fertiliser in it will burn the initial growth when the seed cracks open, so that a seedling will never form.
• Give the seed-raising mix a very light watering.  It’s important not to flood the soil as it needs to be just damp.
• The seeds are then simply sprinkled over the top.  The number of seeds that you use may look like a lot, but they won’t all germinate, and where there are too many, they can be thinned out once they germinate.  Seeds are generally quite cheap, so it is better to seed more than you think.
• The seeds need to be covered with a thin layer of seed-raising mix.  This will keep the seeds moist around all of its sides.  The depth of this layer depends on the size of the seed.  For large seeds such as pea seeds, this might be as deep as 2cm, but for small herb seeds, the depth might only be a few millimetres.  Generally, the rule is to cover the seed by two or three times the thickness of the seed.
• Water the seed lightly again with a mild seaweed solution.  Cover with plastic.  For a propagator, this is simply putting on the lid, but where this isn’t available, make a wire frame and then cover the tray with a clear or white plastic bag.
• Place the tray in a warm spot that’s not in full sun.  In two to three weeks, the seeds would have sprouted.  Once they are about 2cm tall, harden the seedlings by taking off the plastic cover.  Water with a mild liquid fertiliser daily, as once the seedlings have leaves, they need nutrients which aren’t available in the seed raising mix.
• When the seedlings are strong, they can be transplanted into pots with a premium potting mix.  This is simply a process of sliding a thin knife blade under the soil to loosen the roots, picking up several seedlings at once and then planting them at the same depth in the prepared pot.  Water the newly planted seedlings with a seaweed solution and then move them to a position where they will get sufficient light and plenty of water.

SEWING SEEDS INTO COCO FIBRE POTS OR MINI GREENHOUSES

Coco fibre pots and mini greenhouse pods make seed starting simple and gentle on the environment. The pots hold moisture well, keep the soil airy and let young roots grow straight and strong. When it is time to transplant, you simply pop the whole pot into the garden with no root disturbance at all.

Mini greenhouses help keep things warm and humid, giving tiny seeds a steady start. They are great for cooler nights or draughty windows and make it easy to keep an eye on moisture and germination.

For backyard gardeners here in WA, they are an easy, tidy and eco-friendly way to get your seedlings growing.

DIRECT SOWING

Direct sowing is simply planting the seeds directly where they are to grow.  Larger vegetable seeds such as peas, beans and corn suit this perfectly, as do all of the root seeds such as carrots and radishes.

1. Preparation of the soil is the key.  Check the pH to make sure that it is about 6 to 6.5, and if not, correct it as necessary.  Add plenty of organic matter, such as manure and lupin mulch, into the top 5 to 10cm of the soil.
2. Create a furrow (small ditch) in the soil in which the seed is scattered.  Larger seeds can simply be spaced as per the instructions on the packet.
3. Smaller seeds can be mixed with washed river sand and then sprinkled into the furrow, as this allows them to be more evenly spread along the row.
4. Use a rake to gently push the soil back over the furrow. Do not press down.
5. Water well with a seaweed solution.  Do not allow the soil to dry out, as this will cause the seeds not to germinate.
6. Give a boost with liquid fertiliser only once the seedlings have germinated and the second set of leaves has formed. If necessary, thin the seedlings so that there is enough room between them to grow.

PESTS AND DISEASES

Unfortunately, newly germinated seedlings are a gourmet treat for snails and slugs.  Snails will eat a whole row of seedlings so that nothing remains in just one night. Snail and slug pellets are available and should be scattered around and replenished regularly.  If pets or children are in the garden, be sure to use a brand that has a deterrent in it and don’t leave them in piles in the garden where it is easy for them to ingest several at once.

Barriers such as plastic containers with their tops cut off can be successful deterrents for snails, especially if they are sprayed with copper snail repellent products.  Snails do not like to cross copper, so these work quite effectively.  Alternatively, put a small price on the head of every snail and send the kids out in the early evening or morning for a “snail hunt”.  It’s a great way for them to add to their pocket money.

Slaters can be a bit of a problem for very young seedlings as they chew the base of the stem,s causing the rest of the plant to die.  These are hard to deal with as they increase in numbers because of the rich organic matter used in gardens, and are in fact, beneficial as they help to break up the soil.  Barriers will also help to keep slaters from seedlings until they are old enough to not be affected by them.

Other pests such as aphids, whitefly and white cabbage moth are also issues that can be dealt with.  For tips on how to deal with these, visit any Better Pets and Gardens store and pick up a copy of our “Garden Pests” fact sheet.