Growing Cacti from Seed
Cacti are fun to grow and as you will read, very easy to grow from seeds. Cacti come in many forms. Some that grow into enormous giants, whilst some grow painfully slowly. However they grow, cacti are rewarding plants to grow, with their sometimes bizarre forms and amazing blooms.
Easy House Plants
Cacti are well-suited to modern homes, with our bright window ledges and central heating. Cacti are durable, versatile and a great addition to any home. They do not need large pots and often ‘thrive on neglect’. What this means is that they have naturally adapted to very dry conditions, so they do not need watering much. This suits our busy lifestyles as people can easily forget to, or just not have time to water plants regularly.
Obtaining cactus seed
Either collect seeds from your own mature cacti or purchase fresh seeds from a reputable stockist. Keep them in a cool, dry place until you are ready to sow them. Don’t wait too long as most cacti germinate best when the seeds are fresh.
Prepare your compost mix
Sterilise the seed compost. I am using a mix of seed compost, grit and sand. I bake this in my oven on low for a couple of hours to kill off any bugs or diseases, then I allow it to cool before handling it. It is important to heat the compost thoroughly enough to kill any living organisms, but make sure the oven isn’t so hot that your compost starts to burn. Sterilising your pots and compost is especially important if you are using recycled material.
Clean your pots
Sterilise your pots or trays. I always wash my pots in hot soapy water to help eradicate any unwanted guests. Keeping your pots clean should be part of any growing regime, as diseases can easily be transferred between plants in dirty pots.
Fill your pots
Fill your pots with the gritty mix and tamp it down to create a nice smooth surface to sow the seeds on. Don’t push it down too much as it is good to have an airy structure in the compost. Good aeration is vital for root development, and waterlogged compost is a sure-fire way of encouraging fungus, which will quickly kill your baby cacti.
Water the compost a little
I water the compost a little at this point. This will not only help the seeds stay in place, but I think it helps provide the right level of moisture for the several weeks that germination can take, by making sure the lower compost layers are moistened.
Sowing Cactus Seeds
Carefully place the seeds on the moist compost, making sure they are nicely spaced out. I like to give them a chance to establish in this pot, so will only plant about 15 per pot. You can get away with planting many more, but you will need to prick them out earlier. Once you have sown the seeds and covered them, I recommend misting the surface of the pots liberally. This should provide for the young cacti’s water requirements for several weeks, at least.
Protect your seeds
I then cover the cactus seeds with a thin layer of sand. This makes sure they are held in contact with the moist soil and helps with drainage.
Cover the pots or put them in sealed plastic bags. This will help maintain the humid conditions that cactus seeds often need for germination. Open the bag a little every few days to let some air in, and top the water up if it happens to dry out too much. Keep the seeds at a temperature of around 25°C and you should see them begin to germinate in anything from 1 week to 6 weeks, or even longer depending on the species you are growing.
Wait for germination
In my case, I am growing two types of cactus – an Echynopsis hybrid mix, which should produce an interesting range of plants, and Ferocactus wislizenii – The Candy Barrel Cactus which is a lovely cactus.
Enjoy your new cacti!
I’ll post updates as my seeds germinate and my new cacti grow. Why not have a go yourself?
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