Seedlings in propagator trays on a windowsill

Tips for sowing seeds early

Boost your success with early-sown seeds, by following our practical tips.

Sowing seeds early in the year can reward you with plants that will flower or crop earlier than usual.

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To boost your chances of success, there are several things you can do to counteract the effects of low light levels and stuffy indoor temperatures – both of which can encourage damping off. This fungal disease can sweep through trays of seedlings, usually attacking them at roots and the bases of stems, causing them to topple over and die.

When you’re ready to go, check out 10 seeds to sow early in January.


Use a heated propagator

Sowing seed early - using a heated propagator
Sowing seed early – using a heated propagator

Most seeds germinate between 18°C – 22°C, which is not normally achievable early in the year – even indoors. A heated propagator will provide a consistent temperature throughout the day and night, which ensures the best chances of germination without heating the whole room. Models range from budget propagators that provide a basic level of heat, to more expensive models that enable you to adjust the temperature. Always use a propagator lid to keep the heat in and save energy.


Use a growing lamp

With low light levels early in the year, seedlings can quickly become leggy and etiolated. Growing them beneath a lamp will ensure they grow strong and healthy.


Practise good hygiene

Wash pots, seed trays, propagators and anything else that comes into contact with seeds and seedlings thoroughly, then rinse with greenhouse disinfectant.

Scrubbing plastic plant pots clean
Scrubbing plastic plant pots clean

Use new compost

Don’t use up old bags that have been lying around outdoors, even if unopened. For best results, start a new bag of compost.

A new bag of compost
A new bag of compost

Blend your own growing medium

Create your own special growing medium for particular seeds by adding vermiculite, perlite, and/or silver sand or fine grit.

Mixing vermiculite into compost
Mixing vermiculite into compost

Use fresh seeds

Start with new packets of seeds as these germinate fastest and more seedlings result – old seed may not come up at all, wasting time and resources.

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A seed drawer, categorised by month
A seed drawer, categorised by month

Water carefully

Water seeds in after sowing, then water them as sparingly as you dare after that, but don’t let your seedlings dry right out. Check them daily.

Thoroughly watering seeds after sowing, with a rose head watering can
Thoroughly watering seeds after sowing, with a rose head watering can