hether you are a veteran gardener, or you have just noticed a new shade of green on your thumbs and want to explore your options, growing plants and mucking about with nature can be incredibly rewarding. Using seedlings or potted plants from the nursery is quick and convenient, but it's not the cheapest way to populate your garden beds. Growing from seeds is a little more involved, but it can be a lot of fun. If you're looking to save on your gardening bill, you will find seed germination is an incredibly affordable way to create a thriving garden. Not only is germinating seeds budget-friendly, but you can extend your growing season by a few weeks when you start the process inside your home or greenhouse. The controlled conditions on your kitchen windowsill mean your new seedlings don't have to battle against the forces of nature and hungry wildlife when getting started. When you give your plants a head start, you'll reap the rewards of beautiful flowers or a bountiful harvest much earlier. Nurseries generally only keep the most popular plants as seedlings and potted varieties, but you will often find their selection of seeds gives you much more variety and choice. You can also be confident that all your plants are 100% organic when you grow them from seeds.
The USDA classifies Phoenix and the surrounding area as hardiness zone 9b, which means the mercury can drop to between 25 and 30 degrees in extreme conditions. The entirety of Arizona varies between hardiness zones 5 to 9.
You need to be aware of two distinct growing seasons when growing from seeds in this area. In September to December, you should focus your efforts on cool-weather plants like geraniums, snapdragons, lobelia, and pansies for your flower beds.
Winter vegetables for Arizona include spinach, broccoli, artichokes, cabbage, carrots, green beans, and lettuce. You should keep your eye on the weather forecasts as a few weeks of unseasonably warm weather will impact your harvest.
February to May is excellent for warm-season varieties like tomatoes, bell peppers, eggplants, corn, potatoes, and pumpkin. For a flowering garden, you should check out zinnias, amaranth, sunflowers, cosmos, rudbeckia, and coreopsis, to name just a few.
Arizonian soil resembles clay in many ways, which means it's loaded with minerals, but is severely lacking in organic matter. Cacti love it, but most Arizonian gardeners will need to prep the soil before transplanting the seedlings they have raised.
You may need to load your garden beds up with as much as 50% compost before transplanting. Doing this will ensure your new plants have plenty of nutrition available to continue their growth cycle. If you plan on using raised garden beds, you won't have to concern yourself so much with the state of the soil in your garden.
Many vegetables won't cope with the desert heat during July and August, so this might be a good time to add organic matter. The soil will have plenty of time to settle before the start of the planting season in September.
Starting plants from seeds is not difficult and can be very satisfying work. Your shopping list to get started is minimal, as will be your expenses. If you have even a moderate interest in gardening, you will likely have most of the tools you need already. Here's how to get started with seed germination.
To start your plants from seeds, you will need a few essential items:
There will be around 16 cups of moistened seed starting mix for every 22.5" x 10" seedling tray.
Prepare the soil-free mix in the bowl or bucket. Add 16 cups for every tray you plan on filling.
Add water to the mix. Use just enough to get it damp and thoroughly mix it in with the trowel. For best results, use filtered water rather than straight from the tap. Test the soil with your hands. It should feel damp and crumble into small clumps.
When the soil is suitably moistened, it's time to use the trowel to fill each section of the seedling tray. Use enough of the mix to fill a section about a half-inch from the top. Lightly compress the mixture into the inserts, but don't go overboard; you just want to make sure there are no large air pockets.
Set up your plant labels with the variety of each seed. In the first stages of germination, you can use sticky labels to affix to the top of the lid. As the seedlings grow, labels on craft sticks will be more suitable as they will be more visible.
Plant your seeds according to the instructions on the packet. The largest, most uniformly shaped seeds will be more likely to produce healthier plants, so use those first. You will be thinning out the plants later when you select the most robust seedlings for transplant.
Use one of the craft sticks to create a small gully, and then push the seed down into the hole. One trick to keep track of whether you have planted a seed in each section of the tray is to place all your seeds on top of the soilless mixture first, and then go back over and push them in.
Use the mister to moisten the seeds. This step is extra critical if the seeds have not been previously soaked because they won't germinate without a sufficient amount of moisture.
You will want to keep the environment around the seeds as moist as possible, so be sure to put the lid back onto the tray. Clear plastic sheets will create a mini-greenhouse type effect if your trays don't have covers, but you will need to poke a few holes into the plastic to create some airflow.
Find a warm location for the tray to encourage germination. If your home gets cold at night, a seedling tray will provide warmth, or place them near warm appliances or air vents.
Keep a record of what you planted and when. It's also a good idea to write down an estimate of the transplant date. This information will come in handy for next year when you are creating your planting schedule.
Now that you've prepared your seeds for the best start in life, you should regularly check in on them to see how they are doing.
Check each tray daily for moisture levels, and give any trays showing signs of drying out a quick top-up. Even a small stream of water can wash away the seed mixture layer covering the seeds, so keep the mister handy.
Keep an eye out for sprouts, and when you notice a few peeking out through the seed mixture, remove the cover and place the tray under the lights. Once the seedlings are showing, light takes precedence over warmth. The lights should be placed about 2 or 3 inches above the plants and raised as they grow to maintain that distance.
If you have invested in a specialty plant light that also radiates warmth, make sure to take precaution in order to prevent your seedlings from getting too hot.
Keep watering the seedlings regularly but be mindful of overwatering. Gently fill each tray with water and then let the seed mixture wick it away. Keep doing this until you see water sitting on the top of the tray.
Carefully drain the excess water out to avoid overwatering. You can use a mister to topwater your seedlings, but you will want to avoid getting the leaves wet. If you're having trouble, try using a syringe to add water directly to the layer of seed mixture.
The first leaves of a seedling will be small with a simple shape and won't look much like a mature plant's leaves. It won't be long before the first real leaves appear, though, which is when you should add some airflow.
A small fan set to a timer will create a gentle breeze that will benefit the young plants. Airflow prevents fungal diseases and other conditions created by stifled air circulation. You can also stimulate stronger growth by gently ruffling the leaves of the seedlings when you check in on them.
If you have planted multiple seeds in each section of your tray, keep an eye out for more sprouts. If you find some, do not pull them out directly. Instead, clip them off with scissors to give the more vigorous seedling more chances to thrive.
When your seedlings are a couple of weeks away from being transplanted, you will need to 'harden them off to prepare them for life out in the wilds of your garden.
Introduce your seedlings to the outdoors for a time each day, and gradually extend the sessions through the next couple of weeks. They are still delicate and will need some protection from the full sun, so choose a sheltered location. Once a couple of weeks has passed, your young seedlings will be ready for prime-time and life in the great outdoors.
References
[1] https://extension.psu.edu/seed-and-seedling-biology
[2] https://www.britannica.com/science/germination
[3] https://www.gardeners.com/how-to/how-to-start-seeds/5062.html
[4] https://planthardiness.ars.usda.gov/PHZMWeb/
