One by one, we turned the pages, wide-eyed and giddy, feasting on photos of sumptuous flowers, a surefire fix for our winter-starved plant cravings. January has just passed and I'm itching to get my hands in the dirt. Time to pull the black seed suitcase out from under my bed to organize the chaos left by last year's rushed refiling of seed packets.
I organize my seeds by the month they need to be sown, January through June, with March being the busiest month. This type of organization is necessary given our short growing season. Some seeds must be given an early start indoors to allow them to flourish and flower when moved outdoors. I also consider whether the plant requires special treatment. For instance, perennials may like a few weeks in the refrigerator, a process called stratification. If plants require special handling, such as pinching, they must also be started earlier.
Sometimes the seed catalog will indicate when to sow seeds by listing the number of days from seed to flower. This helpful information guides you in planning how far in advance you need to start different seeds. If you'd like a plant to flower in June and it needs 120 days to mature, count back four months to the beginning of March as your starting time. Make sure you don't start too early because you'll end up with light-starved, root-bound spindly plants that take up limited space in your greenhouse, plant shelf or windowsill. The plants may be ready to go into the ground but the weather outside may still be chancy, as is often the case any time before May 15 in our region. It is always best to err on the cautious side and wait.
Perennial seeds take the longest time from seed to flower, so I sow them in January. Once sown, they usually benefit, and won't be harmed, by four to six weeks in the refrigerator to break seed dormancy. They are then placed under fluorescent lights till May then planted in the garden. They bloom in one to three years. Half-hardy annuals should be started in February or March. Half-hardy means they will take some cold nights, but not prolonged cold. A brief dip to 32 degrees at night is OK. These can go into the ground usually by May. Hardy annual seeds can be sown indoors, or directly into garden soil in March or April. Larkspur and poppies actually like germinating and growing in cooler soils, and will survive some cold and snow. Tender annuals and perennials are just that -- tender. A dip to 32 degrees will probably kill them, so wait until all danger of frost is passed before placing these plants outdoors.
Tender perennials can be sown any time of the year and over-wintered indoors. One of the vines I grow, like Cobaea scandens (Cup and Saucer Vine) is a vigorous perennial in Mexico. In my garden, it clambers 20 feet up a ponderosa pine and into its branches. Rather than start the seed each year, I grow it in a pot for the summer and bring it indoors after the first light frost. Tender annuals flower, make seed and die within about four months. I start these in mid-March.
By April 15, I begin taking flats of plants outdoors on warm days for a few hours to acclimatize them to wind and sunshine. Always place them in the shade to start, otherwise our intense sunlight will burn the tender leaves. This process, called "hardening off," toughens the plants by thickening the cell walls in the leaves, preparing them for the challenge of the garden environment. Don't go off and leave them out for the day. If the wind picks up unexpectedly, a common spring occurrence along the Front Range, your tender seedlings could wrinkle up quickly and suffer a real setback.
Before embarking on the adventure of starting plants from seed, ask yourself this question: Do I have the time, for a period of three to six months, to daily check my seedlings, monitor their growth and provide them with water, light and food?
Growing plants from seed is not for everyone. Maybe you'd rather ski or be able to jet off to Mexico in March. If that's the case, be easy on yourself and just buy your plants from a local nursery.
But for me, growing plants from seed is as crucial to my happiness as breathing itself. This month I'll open my seed suitcase and pull a few packets from the February slot. On a day when I've got a whole morning to myself, I'll carry them down to the greenhouse and place them on a corner of the potting table. The propagation mat will come off the shelf, the flats, soils, pens and labels will be assembled with my clipboard notes nearby, and I'll start sowing my seeds.