Gardening at home can be an incredibly therapeutic hobby that builds confidence in your abilities to work with mother nature. All this, to many beginner's dismay, comes after the hurdle of seed germination. It so happens that plants, much like animals, are the most vulnerable within the first month of their life and the degree of their success heavily depends on how well it started it's life from a seed. As with anything in life, it can be insurmountably difficult to succeed without the proper information so keep reading to find out the best way to germinate and start your gardening journey strong!
Let's start off with what may be obvious in retrospect: not all seeds are made equal. As an extreme example of this let's take a look at two wildly different plants: Arugula and Oak Trees. On one hand, Arugula seeds are barely larger than a a grain of sand and only takes about 2-3 days sprout. Conversely, a larger oak seed has a tough exterior and it takes 75+ days to germinate! What all this means is that you have to do your due diligence as an expectant plant parent and research what your seed needs to grow big and strong. Here's a rundown of some of the most important germination factors in no particular order:
2. Planting Seed Depth
3. Light or Dark Germination
4. Nicking or Pre-Soaking
1. Temperature plays a huge role in plant metabolism and, along with moisture, greatly affects whether a seed will germinate or not. Many brassicas (Lettuce, romaine, arugula, chard, kale) like cooler temperatures between 65-75 F (18-23 C). As a rule of thumb, warmer temperatures are better for other seeds as it speeds up plant metabolism, but there is a definite point where it's too hot. To be safe, you should not exceed 85 F (29 C). Many gardeners swear by a germination heating mat under their germination tray that is set at 85 F to quickly boost germination success.
2. Planting Seed Depth can vary a good deal between seed varieties, but as a rule of greens thumbs you can expect that the smaller the seed, the more shallow the planting depth. For example a watermelon/cantaloupe seed does great about 1/2" under the soil, but smaller seeds such as lettuce prefer a much more shallow 1/8". You should note that most seed packets will specify the planting depth so make sure to read it in its entirety!
3. Light or Dark Germination is an often overlooked variable when germinating plants. Luckily most edible Brassicas and other food crops prefer dark germination so it's not often that incorrect lighting is the reason your seeds may not be germinating. This is true unless you're planting the small amount of plant families that prefer light during germination. These include many popular flowers like petunias, begonias, and other plants like the coleus and ficus.(https://www.thompson-morgan.com/effect-of-light). As for the dark-germinating plants, it's best to keep them in a humidity dome that is in a dark room or closet, or simply cover with a light-blocking material. As soon you see the first signs of the plant breaking the surface of the soil be sure to bring them into the light to let them know they made it to the sun!
4. Nicking or Presoaking (also know as scarification) is a process used by farmers on seeds that have tough exterior shells. Nicking and/or presoaking encourages the seed to start breaking out of it's shell and can greatly decrease the time of germination for certain seed types such as Hibiscus, morning glories, and some Solanaceae plants. The rule of thumb is if the seed has a waterproof coat, it may benefit from nicking and presoaking. As a caveat, be sure to nick the side of the seed opposite of the hilum, the little dot where the seed was attached to the mother plant. Harming this "belly button" may damage the seed instead and halt any chances of germinating!
5. Watering is often the most difficult parameter to get just right when germinating your plants. Too much water and you'll promote harmful bacteria and fungi that will decay and rot the seed, too little and the seed will dry out and refuse to germinate. To remedy this, many farmers turn to substrates that have the optimal water retention or drain well if over watered. Coco choir is my personal favorite as it is hard to over water, but many have had success with a 50% soil and 50% perlite mixture to start their seeds. The substrate should be similarly moist to a freshly wrung out towel.
My preferred way to begin seeds it to use a germinating tray from companies such as Jiffy. it comes with a tray of compressed coco-choir pellets that you simply hydrate, place the seeds at their correct depth, and cover with a moisture dome then place them in a dark and warm closet. With this information you now have the knowledge to successfully start a seed at your disposal. Once germinated keep an eye on your lighting environment and watering. Carefully observe your seeds as they will communicate any problems in their own language; if a plant is stretching (stillating) it needs more light, if the plant is drooping you're either giving it too much water or not enough.
Finally the biggest piece of advice to be a successful gardener is to keep at it! Each failure is actually a lesson in disguise. Fail hard and fail fast and you will quickly learn to speak the language of plants faster than you can imagine. If you think of gardening as a trial in patience, humility, and gratitude for life and you'll be surprised how much plants are helping you grow just as much as you help them.
Cheers and Good Growing!