Growing veggies from seed (successfully!)
Why grow from seed?
©Maria Ciavarella, My Green Garden
It’s good to grow many veggies from seed for a variety of reasons:
- Its fun – and it always exciting seeing the seeds germinate.
- The variety available from seed is much greater than seedlings.
- It’s far cheaper buying a packet of seed than a punnet of seedlings.
- Some are dead-easy to grow from seed and others just don’t do well when transplanted from seedling punnets.
- Excess seedlings become another “commodity” to take to swap-meets.
- If growing heirloom varieties, seed saving can be done and so you minimise the inputs into your garden – closing the loop.
time bracket. It is also more time consuming, sometimes with a few extra steps involved before the
seedlings are ready to plant.
What is involved?
This is one of the most critical factors when getting seeds to germinate. Warm season veggies
especially need heat to activate germination.
Check soil temperatures by:
- Using charts to indicate when the timing is right
- Using a soil thermometer for more accurate readings
- Using the palm of your hand on the soil to feel the warmth
- Germinating seeds indoors
- Use a hot spot in your house e.g. top of an indoor hot water unit; or the top of the refrigerator
- A sunny window sill
- Using a purpose-made heat bed for seed-raising
- Using an outdoor greenhouse structure.
Direct sowing in ground
This is used when soil temperature is in the correct range for:
- Easy-to-handle seeds e.g. legumes (peas, beans, broad beans); cucurbits (e.g. pumpkin, cucumber, melons); and sweet corn
- Easy to sow seeds e.g. lettuces
- Seedlings that suffer being transplanted
- e.g. carrots and parsnips (roots become distorted)
- basil, spinach (suffer transplant setback)
Hints for sowing carrots
I use fine tea leaves and mix the carrot seed with that. You could also use fine sand. Make shallow drills in finely tilled soil (one that has not been recently fertilised) and dribble the seed/leaves mixture in the drills.
Water carefully. Cover the drill with some shade cloth or a narrow plank of wood to help avoid the seed drying out. Check regularly to see if germination has occurred and lift the cover as soon as you see green. Thin the growing stems to about 5cm apart and then eventually to about 10cm apart. If this is all too hard, there is carrot seed tape available which makes it very easy to sow.
Hints for sowing basil and spinach
Sowing in-situ is dicey with these as they are very temperature dependant (basil needs heat, spinach prefers cooler soil temps). Instead of directly in the ground, use the 2-step method described below (using several seeds per biodegradable pot) in an environment where you can provide the correct temperature. When the seedlings get big enough, plant the pot in the ground.
You could also sow them directly in the ground (at the correct temp) but cover the rows with fine mesh or similar to keep out marauding fauna pests until the seedlings can look after themselves.
In direct seed sowing (2-step)
This is used for seeds that are
- grown early, before it is warm enough or cool enough
- or that are very small to handle and may get lost in the garden
You can use;
- a seed-raising mix, available at nurseries
- sterilised compost
- make your own from a 50:50 mix of fine dry cow manure: propagating sand or 50:50 coir peat: propagating sand
- good potting mix for larger seeds is ok.
Sow the seed in the moistened mix in a biodegradable pot and cover seed with twice its depth of the mix. Water using a fine mist. Do not allow to dry out as this will kill emerging seedlings. Use seedling punnets for lettuces, onions and silver beet.
The cotyledons (baby leaves) will appear first, followed by the first set of true leaves. Once the seedlings appear, they will need feeding by you in the form of weak seaweed solution or a diluted liquid organic tea. When the seedlings are about 10 cm tall, or when they have two sets of true leaves, plant the biodegradable pot straight into your prepared garden bed; or (from punnets) prick out each seedling individually and pot this into the garden bed.
In direct seed sowing (3-step)
This is used for seeds grown early, before the outdoor soil is warm enough.
Sow the seed in individual jiffy pellets and keep them warm.
When the second set of true leaves appear, place the jiffy pot straight into a biodegradable newspaper pot or individual tube pot. The seedlings will continue to grow in these while waiting for the soil temp to warm up.
When the soil has warmed up adequately, plant them into their
permanent position. You may still need to protect them from
cold nights if you are planting early for summer.
Hints for success
- In step 1, plant what you need plus a few more in case some fail to thrive.
- Water the seedlings in step 2 with a cooled chamomile tea. This helps prevent “damping-off”, a fungal problem with seedlings.
- Make your own “watering can” suitable for seedlings using a plastic milk bottle with holes pierced in the lid.
- To warm up outdoor soil, keep mulch pushed away so the sun can heat the dark soil.
- Some seeds benefit from being soaked overnight prior to planting out (e.g. beetroot, legumes, sweet corn).
- Anticipate a 6-week process up to the point of planting out, compared to buying seedlings.
- Collect toilet paper rolls for sowing sweet corn or sunflower seeds as they like to put down deep roots.
- For most vegies, it is worthwhile growing from seed but for others, such as onions, you get so many in a punnet that you may as well buy seedlings, unless you are after a particular variety not available as seedlings. If you do grow from seed, it’s easier to use the in-direct 2-step method, planting out after the initial germination (no need to plant on before going into soil).
- Some seed need to be fresh and should be purchased every year (e.g. sweet corn, parsnip).
- Some seeds are now available in seed tapes or seed mats, making the spacing and sowing much easier.
For instructions on making the biodegradable pots out of newspaper:
Timing for seed sowing
(Reference: Sow What When Chart - Diggers)
|COOL SOIL 10oC||SOWING METHOD||MILD SOIL 12oC||SOWING METHOD|
|Broccoli||Indirect (2-step)||Cabbage||Indirect (2-step)|
|Leek||Indirect (2-step)||Cauliflower||Indirect (2-step)|
|Onions||Indirect (2-step)||Celery||Indirect (2-step)|
|Pak Choy||Indirect (2-step)||Lettuce||Direct or Indirect (2-step punnets)|
|Peas||Direct||Rocket||Direct or Indirect (biodegradable pots)|
|Radish||Direct||Silver beet||Direct or Indirect (2-step)|
|Spinach||Direct or Indirect (biodegradable pots)||Coriander||Direct or Indirect (biodegradable pots)|
|Spring Onion||Indirect (2-step punnets)|
|WARM SOIL 15oC+||SOWING METHOD||VERY WARM SOIL 18oC||SOWING METHOD|
|Sweet corn||Direct (toilet rolls)||Chilli||Indirect (3-step)|
|Cucumber||Direct or Indirect (biodegradable pots)||Eggplant||Indirect (3-step)|
|Pumpkin||Direct or Indirect (biodegradable pots)||Rockmelon||Direct or Indirect (biodegradable pots)|
|Tomato||Indirect (3-step)||Watermelon||Direct or Indirect (biodegradable pots)|
|Zucchini||Direct or Indirect (biodegradable pots)|
|Basil||Direct or Indirect (biodegradable pots)|
Notes prepared by Maria Ciavarella, My Green Garden, February 2013 for Moonee Valley and Hobsons Bay City Council’s My Smart Garden program.