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Horticulture 1000
HT1091 - Plant propogation 1 - Sowing seeds in open ground
Seed dormancy Thinning seedlings

Sowing seeds in open ground

You can grow seeds in containers or directly outdoors in the garden. Some seed, especially seeds of root vegetables, must be sown directly where they are to grow. Plants like carrots or radish don’t grow well if the seedlings are transplanted. They don’t like their root system being disturbed.

One problem with direct sowing in the garden is that you have little control over the weather, so seeds should be sown at favourable times of the year.

Most seeds are sown in spring, when the soil and air temperatures are warming up but there is still plenty of moisture in the soil to help with germination.

More hardy plants can be sown in autumn when soil temperatures are still high. In autumn there is more moisture in the soil than in summer, due to autumn rain and less evaporation of water from the soil.

Watch the video


Successive sowing

Seeds  sown directly outdoors are often fast growing vegetable crops. To achieve a  continuous supply of vegetables small and frequent sowings of seed can be made  over a period of time. This is called successive sowing. This is useful  for crops that don’t store easily like cabbage and lettuce.

Calendar showing dates for the successive sowing of lettuce seed

Calendar showing dates for the successive sowing of lettuce seed.

You also don’t want all your carrots ready to be harvested at the same time, so plan to sow some seeds now and then some again in three weeks time.

Complete Activity 5A in your workbook.

Sowing seed outdoors for a winter garden

You  will need:

  • a hoe
  • a rake
  • a watering can or hose
  • labels
  • carrot, broad bean, silverbeet, and radish seed and a small amount of lettuce seed
  • your diary from HT1021 or a small 3B1 notebook where you can record your practical work activities
  • compost if available.

What to do

Follow these instructions to successfully sow some seeds into your plot to grow a winter vegetable garden. (Only complete this task if the soil temperature and moisture is suitable.)

Level the soil that has already been dug over with a rake
  • Level the soil that has already been dug over with a rake. This will break it down into very fine pieces known as a fine tilth.
  • Dig in some compost if it is available.
  • If you did not add some general garden fertiliser to your plot when it was cultivated then you could do so now.
  • You will sow some of each of radish, carrot, silverbeet and broad bean seeds.  Sowing lettuce seed directly into your plot is optional as you may have  seedlings to transplant from HT1021. Remember to sow the taller plants on the  west side of your plot and run the rows from north to south to ensure that no  plants are shaded.
Tie a stringline tightly between two sticks, then sow the seeds in a furrow or drill
  • Tie a stringline tightly between two sticks to mark a straight row running north to south.
  • Sow the seeds in a drill. Make this by dragging the corner of a hoe blade, stick or rake through the soil. Broad bean seed can be planted in a furrow. A furrow is wider and deeper than a drill.
Sow seeds to a depth of twice their own diameter
  • Sow seeds to a depth of twice their own diameter. Seed that is sown too deep will not have enough energy available to allow the seedling to emerge through the soil  surface. Sprinkle fine seeds like carrot and radish evenly along the drill by rubbing your thumb and finger together. Larger seeds like beans are sown one at a time by hand so you can space them out.
  • Follow  the table to see how to sow each kind of seed correctly.
SeedsDrill depthSeed distance in rowsRow distance
Radish 1 cm Fine seed sprinkled along row 30 cm
Carrot 1 cm Same as above 30 cm
Lettuce 1 cm Same as above 30 cm
Silverbeet 2–3 cm 1 cm apart 30 cm
Broad beans 5 cm 10 cm 30 cm
Push a thin layer of soil over the seeds
  • Use the flat blade of the hoe or rake to push a thin layer of soil over the seeds.  Press the soil firmly with the back of the blade to ensure good contact between the soil and the seeds.
  • Water  the rows gently so the seeds won’t wash away. Use a fine rose on the watering  can or hose. Don’t over water.
  • Label each row so you can tell what you  have sown. Use an iceblock stick or piece of wood or a piece of plastic such as  part of an ice-cream container.
  • Sow half the carrots now and half on  the date you have worked out in activity 5A.

Complete Activity 5B in your workbook

Key points   Key points

  • Some seeds can be sown directly outdoors. This is useful for plants with fragile root systems.
  • Sow seed to a depth of 2 x the diameter of the seed.
  • Successive sowing is when seed sowing is planned to achieve a continuous supply of crops.

What's next?

Go to: 6 Thinning seedlings.

Seed dormancy Thinning seedlings