The growing season is the time between the last freeze in spring and the first freeze in autumn. The average last occurrence of temperatures 32 degrees or lower for Fargo is May 15, and September 26 is the average first date in the fall when the temperature drops to 32 degrees. This means that Fargo has a mean freeze-free period of 130 days. Although this is 10 days longer than in Minot, it is still short compared to southern states. Because those dates are average, there is an equal chance that the temperature could fall below 32 degrees a few days sooner or later than those dates.
If we have sunny windows or plant lights, we can start some seeds and plants indoors to make the most of the season. Start the seeds of alyssum, moss rose and salvia very early in April. Seed zinnias, marigolds, calendula, celosia and gaillardia later in the month. Figure back from the frost-free date the number of weeks the seedlings need to germinate and develop as stated on the seed packets.
Keep the lights about six inches above the seedlings after they sprout, and raise them as the little plants grow. Young seedlings need a consistent supply of moisture to get established, so check them every day. It is better to give them a light soaking every day than to flood them once a week, as too much water can hurt them. Don't fertilize until you see the second set of leaves, which are the true leaves. Growing medium is primarily peat moss that fertilizers and water run through rapidly, so feed with a half-strength soluble fertilizer with a high middle number to promote active root growth.
Plant or repot geraniums that were stored over the winter. Last fall I dug out 18 geraniums, shook off the soil from the roots and stored them upside down in a paper bag in a cool, dark place. I potted up 12 that looked somewhat promising and now eight of them are leafing out. It will be interesting to see how well they will do this year. Prune potted geraniums and coleus plants and root the 4 to 6 inch cuttings in moist vermiculite, perlite or well-drained potting mix.
Start planting tender bulbs like canna, dahlia, tuberous begonia and caladium if you have enough room. Although you can plant them in the ground when the weather permits, they will bloom earlier if you can give them a head start. Use a potting mix of half perlite or vermiculite and half peat or a well-drained potting mixture. Plant tuberous begonias with the hollow side up and with the top even with the soil surface. Canna rhizomes should be buried so that the upper half of the rhizome is just above the soil surface and the eye is facing up. Plant dahlias in small pots with the tuberous roots covered and the eyes one inch deep. The knobby side of caladium tubers should be up and covered with one to two inches of soil. Water each and place them in a warm place. Put them in a sunny spot as soon as they sprout.
Hardy bulbs are probably beginning to come up outdoors. Keep some mulch handy in case of extreme temperature drops. I place evergreen boughs from my Christmas tree over areas that tend to warm up too soon to keep the ground frozen. Daffodils are often overlooked and the buds can be damaged, preventing them from developing. The emerging shoots of lilies are very sensitive to freezing temperatures so cover them with mulch if they come up too early. Lily bulbs can be planted as soon as the soil is workable. Keep the bulbs in peat moss in a perforated bag in the refrigerator until you can plant them. Lily bulbs are never dormant so they should be planted as soon as possible.
It is a good idea to get out and prune your shrubs and trees while the ground is still frozen and the shrubs are dormant. Pruning should be done every year, but you do not want foot traffic to cause soil compaction when the ground has just thawed. Don't prune spring blooming shrubs, like lilac, forsythia and bridal wreath spirea at this time. Wait until after they bloom.
While you are waiting for warm, dry weather, you still have an opportunity to attend a garden seminar. There are Gardening Saturdays in Underwood, Minn., on April 5 and at East Grand Forks on April 12. Pre-registration for EGF can be sent to: NDSU Extension Service, Attn: Gardening Saturday, 151 South 4th Street S302, Grand Forks, N.D. 58201-4715 along with a fee of $25, which includes lunch. Each of these events has four sessions with multiple topics from which to choose. I highly recommend them for great information and a good time.