Growing plants from seed isn’t for the faint of heart, it takes skill, patience and plain and simple dumb luck. After collecting plants for many years now I’ve noticed it’s becoming harder and harder to find something new. I’m fortunate to live in a city with an incredible variety yet sometimes I just can’t find what I’m looking for. Luckily with the aid of the Internet, all you have to do is ask. If you look hard enough you can find seeds for almost anything online. While rare and exotic seeds can cost a little more than you’d expect, they’re still significantly cheaper than buying plants. That is, if you can successfully germinate them. While growing plants from seed isn’t rocket science it does take a little extra care to be successful. Here are some techniques I’ve learnt from study & trial and error.
An important step in growing strange and exotic seeds starts with good quality seed. For best results, the fresher the better. Some seeds loose viability extremely quickly, fresh seeds have the highest germination rates. Once collected remove the seeds from the chaff/debris and store in a dry location. If the seeds are in fruit, remove the seeds from the fruit, clean and dry out before storing. Increased longevity of the seeds can be achieved by storing them in the fridge. Large hard seeds will benefit from being soaked for 24hrs prior to sowing and on occasion nicked or scared so the seedling can break free. If you’re unsure of how deep to plant your seeds, the general rule of thumb is as deep as the seed is large. For flat seeds like lily / agave or yucca planting try them vertically, not flat. Tiny dust like seeds should be mixed with sterile sand so as to aid even dispersal over the soil medium. While one might be tempted to seed individual pots with individual seeds, I find it more successful to seed solitary pots. Seedling seem to thrive in the company of others.
I recommend investing in a good seed starting mix from your local garden center. If you can’t find a seed starting soil, cactus soil also works well too. The most important part being that the soil is well draining, often having a larger percentage of sand/perlite then other potting mixes. After one has acquired the proper soil you’ve now got to ensure it’s sterilized. Nothing’s more defeating then seeing your seedlings appear, only to rot off a day later. Most bagged soil is supposed to be sterile, but if you’re extra keen you can put it on a baking sheet and bake for 20 minutes in the oven. It will fill your house with a wonderful earthy smell reminiscent of dirt and home baking. After 20 minutes all bacteria in the soil should be dead, thus raising your odds of success. Now that you have the right soil, it’s time to make sure everything else is clean too. Giving your pots a quick bath in boiling water will ensure they aren’t harboring any bad bacteria. It also would be a good idea to wash your hands prior to sowing as well.
Fill your clean pots with clean soil and get ready to create life. If you have a fungicide on hand (garden sulfur works great) sprinkle some over the soil medium to prevent dampening off. Now gently wet the potting medium to dilute the fungicide dust and also settle the soil. If the soil has settled lower then you had expected top it up, fungicide it again and wet until perfect. Wetting the medium before sowing your seeds will prevent the tiny seeds from floating off to the side of the pot.
Now that the soil is moist, sprinkle your seeds evenly across the pot. Not knowing the specific growing requirements of the plant, I find it best to make sure some seeds are exposed in the light, and some are below the soil. Agitating the surface of the soil will make sure the seeds find a little bit of both environments. Some seeds require light to germinate while others darkness. Now that your pot is seeded place it in a zip lock bag or put a clean plastic lid over it. What we’re trying to do here is increase humidity. The tighter fitting the better, you’ll know you’re on the right track if you see condensation collecting on the walls of the plastic. Humidity is key. Plastic sushi containers & to go sandwich packaging make great sealing seed starting trays. Place your seed tray on a warm sunny windowsill, or under grow lights and wait. Many seeds will germinate within the first week others two or three. Some take much longer. Patience is key and you shouldn’t throw away failed seeding projects for at least a year. Over the days and weeks, check your trays for signs of growth, if the soil dries out make sure to give it a drink. To water once seeded, place your seeding tray in a larger container of water and let it absorb via capillary action.
Once seedlings appear and begin to grow, cut a few holes in the plastic to let fresh air in. Over the course of a week you can slowly but surely adapt them to the outside world, eventually removing the plastic all together. If germination was successful and the tray is looking overcrowded, avoid the urge to transplant your seedlings. I don’t know what it is about over crowded seed trays but the little newborns seem to thrive in these close conditions. Premature pricking out sometimes leads to failure, I find it much safer to transplant once the seedlings start to look like little plants. Even though they might look deformed in these tight conditions, once you transplant them they’ll correct themselves. Another thing to keep in mind is to avoid changing the environmental conditions of your seedlings too quickly after they sprout. I often don’t heed this advice and move my freshly sprouted tray of plants only to shock the poor little guys and loose half the litter. The plants sprouted on that window sill and will do their best in the same location.
For succulents and bulbs a thin layer of sterilized crushed gravel on the top of the soil is a nice touch that should increase your odds. If you notice moss or algae growing a spray of diluted rubbing alcohol will eliminate them without hurting your seedlings. Some seeds from cold climates require a cold period to sprout properly, others need a smoke treatment. A quick research into the plant’s native habitat might give you some clues.
Last but not least, properly label your pots. We might like to believe we have a good memory but 3-6-9 months later you might not remember. Sometimes I use codes and write my info inside a book.
Granted this is a pretty thick manual on seed sowing and you can change the recipe however you see fit. Depending on what I’m growing I skip a step or two, but have known to regret such decisions. Pansies, petunias and parsley might not require such rigorous methods, but if your sowing the strange and unusual, why not give yourself the best chance of success. Having just paid $1.00 a seed for some Dendroseris litoralis seeds and I don’t see a point in taking shortcuts.