Pricks And Mortar – Building Your Cacti Collection by Growing from Seed.
Growing your own cactus plants from seeds is an easy and cost-effective way to bulk up your collections. Rather than get 1 or 2 new plants by propagation, you can get 10x that by growing from seed. By growing from seeds, you also get stronger and more resilient plants than you would get from cuttings, and you can sometimes get natural variations from the parent plant, so your collection never looks bland!
Growing from seeds is relatively straight forward but does take a little bit of patience and care. Here’s a quick lesson in spike-ology to help you get straight to the point
Before you do any work with cacti, you should always take some safety precautions to avoid getting pricked by your plant's spins. The easiest thing to do is to wear gloves to protect your hands and fingers. You can also have tools like tweezers, clothes, and spoons around to help you avoid touching the plants.
When it comes to getting your hand on some cacti seeds to plant, you have two options.
The first option is to harvest seeds directly from the plants themselves. These could be plants you already own, or those of your friends, family, or neighbours. Be sure to ask first though before you pick any fruits from plants that aren’t yours.
Growing from seeds you have collected yourself is the cheapest option, but it does require a little leg work to get them. You’re also limited to only being able to grow plants that you can get seeds from, which rules out any rare or exotic plants.
To harvest seeds from the plants, you’ll need to wait until the plant flowers and fruits, so there’s only a small window of time when you can actually get these seeds.
You’ll need to pick the fruit off your cactus when it is ‘ripe’, which will depend on the species, but, generally, fruit that is ready to harvest will come off easily with a little tug. Once you’ve got the fruit, cut it open and remove the seeds with tweezers by scrapping the flesh off the skin.
The second option for seeds is to buy them. You can get these from a gardening store in person on online. The benefit of buying seeds is that you save the hassle of harvesting and you can get them any time of the year, but it also means that you can select any variety you want, and you can decide on species that work best for where you want to grow them.
Whether harvested or purchased, the next step is to sow your seeds.
Fill up a container with a free draining planting medium blend or specific cacti and succulent potting mix. Make sure the container is big enough to hold the seeds you want to plant and that it can be placed in a warm, light location. This container can be a tray or Tupperware container, or a pot. If it holds moisture and can be covered, you’ll be fine.
When you’re ready to plant the seeds, pre-wetting the material is a good idea to help the seeds ‘stick’ to their new home. Once they’re down, cover them with a light scattering of the soil or some sand, just enough to hide them, but not so much that they’re buried. Buried cacti seeds will run out of energy before their first shoots can break the surface.
Covering your seed container with plastic wrap or a clear lid and placing it in a sunny area once you’re done planting is a good way to maintain moisture and temperature levels for your seeds. The sweet temperature spot for cacti seeds is between 20-24oC.
Remove the cover as needed to add water to keep the moisture levels up. You want the potting medium to dry out between waters, but never to the point of being completely moisture free. The time between watering will depend on your cacti variety and the amount of sun you’re exposing them to.
After a few weeks, you should start to notice your seeds germinating. This will be a few spikes or stems at first and can take up to a month with slower-growing varieties. Once you notice growth in the seeds though, you can strip off the container’rs covering during the day and let some fresh air in.
If temperatures in your area get cool overnight, you’re best to cover things up again once the sun sets, but if you live in a warmer climate, you might be ok to remove the cover altogether. Keep in mind though that once you remove the cover, you’ll need to increase the watering frequency to maintain appropriate moisture levels.
After another month or so, or when your seedling is now a bit bigger and has some fleshy parts as well as some spikes, you can definitely remove the cover and not look back!
After around a year of growth, your seedlings should now be big enough to re-pot. The bigger the plant, the easier they are to work with, but you also don’t want your seedlings overcrowding each other in one container, so it’s best left as an educated guess as to when you should do this.
Using gloves and a spoon, hold your cactus seedling and scoop all the potting mix around, making sure to get all the soil around the root system. Place the seedling into its new container and top it up with some fresh cacti/succulent potting mix. Give the soil a pat down and a good drink of water, and you’re done.
Let your seedling rest in a warm, shady place for another month or so before moving it into it’s long-term home. This will let the seedling get over any transplant shock and will let the roots work their way into the new potting material. This is important if you’re intending to place the plant in an area with wind or where it could get knocked over. A developed root system will help anchor the plant down.
You’ll need to keep watering the seedling more than normal whilst it recovers from the transplant shock, but you can reduce this as it becomes more established. You can also compliment this watering with cacti-specific liquid fertilizers can quicker this establishment.
