Spring is here! The weather is warming, some of my wildflowers are already starting to bloom, and I have been absolutely delighted with all of the excitement that comes with seed starting season. It never fails to be a magical experience for me to be able to take these tiny unassuming things called seeds and watch them grow into beautiful and delicious plants.
While a lot of joy comes from seeing seeds sprout, it can be equally disappointing when they don’t grow. While many seeds don’t need any special attention, some seeds require extra thought and proper conditions. Here are my favorite tips and some things to consider when starting seeds.
Start with safe soil. I fill a pot with soil and pour a kettle of boiling water through it to kill any potential plant pathogens. Once it has cooled I mix in a few big dashes of ground cinnamon to act as a gentle anti-microbial. These two steps help to reduce or eliminate white mold that attracts fungus gnats, and help prevent seedling death from plant diseases like damping off.
I’ve found that most seeds can benefit from soaking in a small cup of water for a few hours or overnight. This is a way of getting through that tough seed coat by softening it with a good soak. Some seeds require warm water soaks for an extended time, and this can be achieved by placing your cup on a heat mat. Heat will make the water evaporate faster, so if I’m seed soaking with heat I will typically fill up the cup.
While a short time in water to seed soak is helpful, your new plants will need to breathe as they grow roots that require oxygen. Make sure your seed starting containers allow for good drainage so they are not sitting in water as they grow.
Many seed packets will refer to the last frost date in reference to when seeds should be planted. To be on the safe side, assume a last frost date around mid-March for Patterson. Many planting charts for when to start garden vegetables throughout the year can be found online with a simple search for planting charts for zone 9b. Specifying our USDA growing zone will help you find information tailored to our climate.
Temperature While many seeds will germinate fine at room temperature, some require cold stratification or heat to actually get growing. If you’ve had trouble with a specific type of seed, consider looking into the temperature requirements for germination.
Cold stratification can be achieved by placing your seeds on a damp paper towel in a plastic container in the fridge or freezer for a specified amount of time. Some seeds prefer to be stratified in the freezer, while others can only handle fridge temperatures. A quick search online will help you find out which to use for your seeds. Be careful to use a very clean container and clean hands or you may end up growing microbes in your fridge instead of seeds. Cold stratification times vary, but usually range from a few weeks to a few months. If you’ve ever had trouble getting apple seeds to sprout, try cold stratification.
Heat can be applied via a heat mat or lamp. If you are using heat, make sure you’re using safe, water-resistant equipment. Heat will make your soil dry out faster so keep a close eye on things. Pepper seeds will greatly benefit from heat. If you’ve struggled with germinating pepper seeds in the past, try seed soaking, and use a heat mat. Pepper seeds require a lot of patience. While some varieties germinate within a couple of weeks, I’ve had other pepper varieties take over a month to sprout.
Humidity - Seeds need even moisture while they’re germinating, and this can be hard to achieve, especially when using heat. A humidity dome will help keep them happy until they sprout and should be removed once leaves have appeared. Making a humidity dome can be as simple as turning a clear container upside down over your starts. I like putting my seed starts under dollar store cake domes to keep even humidity.
Scarification - The outer coats of seeds are built to protect them. Some seeds are adapted to have their coats ground or chemically weakened by animals before starting to sprout. Since purchased seeds have not passed through the gut of an animal, this needs to be recreated in some cases. I like to use a nail clipper and file that are only used for seeds and kept clean regularly to nick the seed coat to let in water and start the germination process. Be careful not to nick the radicle (usually a point, nub, or dimple) where the root will be coming out. Not all seeds need scarification, but many seeds can benefit from scarification. I’ve found that I get a higher rate of germination, and a much faster germination time when I use scarification. Large, flattish seeds like squash, gourds, and some melons are good candidates for clipper scarification. Rounded seeds like beans and peas are easier to nick with a file. For seeds that recommend scarification in their germination instructions and have particularly tough coats, scarification may be easier after seed soaking.
Depth - Planting depth matters! Depth affects a seed’s exposure to moisture as well as light, and can affect the temperature particularly when direct sowing outdoors. Some seeds need light, while others need the dark. Suggested planting depths can usually be found on the back of a seed packet or online, but you can also make a good estimate based on the size of the seed. Smaller seeds typically get planted shallower, while bigger seeds get planted deeper. A garden dibber is a measurement tool that will help you make sure you get the depth right every time. Dibbers are available for purchase online, but you can make your own from an unused chopstick or a wooden dowel. Mark one end with typical seed planting depths (⅛”, ¼”, ½”, 1”, 1½”, 2”), beginning with the shallowest depth near the tip. Push your dibber into the soil to the desired depth to make the perfect depth pocket for planting your seeds.
Light - If you are starting seeds indoors a bright, South-facing window will help you get things going, but your seedlings will eventually require more light so they don’t get too long (leggy) while reaching for the sun. Move them to a sheltered area outside until they’re ready to plant. A milk jug can be cut in half to make an easy DIY mini greenhouse to protect seedlings outdoors. Alternatively, LED grow light strips are easy to install and can be acquired for a reasonable price to continue growing indoors longer. If your seedlings do get leggy, you can try just planting them a little deeper.
Tools - Having your tools organized and collected before you sit down to plant can make things much easier. In addition to my garden dibber and scarification tools I usually like to collect cups and a pitcher of water for seed soaking, and a small paintbrush to help move around small seeds that are difficult to handle.
If you’re looking for some interesting flavors and colors to add to your garden try easy-to-grow-from-seed favorites like nasturtium, rainbow Swiss chard, or red okra. Nasturtium tastes like a mix of spicy garlic and artichoke hearts. The spicy leaves are excellent pizza toppings or added to spring rolls. Mild nasturtium flower petals can be used to decorate spice cakes, or chopped and sprinkled over dishes as a garnish. Rainbow Swiss chard is an edible garden showstopper and can last for a year by just harvesting the lower leaves as it continues to grow. Rainbow Swiss chard tends to have a milder flavor than its all-green counterparts and is slightly salty which brings out the flavors of the other ingredients in the dishes that it is added to. Okra plants absolutely adore our high heat summers! I especially love red okra for its deep red color and large hibiscus-like flowers. Use okra in stir fry, or soups and stews as a thickener.
Whatever you choose to grow, I wish for you the joy that comes from seeing those beautiful baby sprouts! Happy spring! Now, let’s get growing!