Your blogger is impressed: row upon row of trenches in gently rolling fields, THOUSANDS of dahlia tubers nestling in new beds and then lovingly covered over with beautiful sandy loam. (As one whose gardening areas are all on gravelly glacial leavings, where soil has to be built up with composed leaves and mushroom compost, it's hard not to look over these fields and feel murderously envious. No wonder beautiful dahlias come out of those fields, and thriving tubers emerge at the end of the season.
SOME PLANTING TIPS and advice for the care of dahlias came out of that session at the farm as well. Here's advice from the planters at the Farm:
• Prepare the soil well. Manure (well rotted), compost, and peat moss all help create the rich, loose soil that will nourish your dahlia tubers and enable them to thrive and bloom abundantly. Good drainage is a must for dahlias; standing water or heavy clay soil will encourage rot or disease, so add sand if your soil is clay-ish or your planting area isn't well drained.
• Protect dahlia tubers and the plants, when they emerge, from adverse weather conditions. Be sure the danger of heavy frost is well past before you plant (April 20 to June 15 in most zones). In areas with late frosts, starting dahlias in pots in a greenhouse is a good option. If you are in an area that gets significant wind, be sure stakes are in place to help support the mature plants. In almost any area, staking is necessary for the largest of the bloomers.
• Position tubers correctly. Space tubers according to plant size; giants and medium dahlias should be three feet apart and six inches deep; small, miniatures and pompon dahlias can be four inches deep and spaced two feet apart, and mignon singles can grow even a bit closer together for dense borders. Tubers should be laid in the ground horizontally, with the eye sprout facing upward. Cover carefully and do not pack soil hard. (It's a good idea to place a support or identification stake before you cover the tuber so you don't damage it pounding a stake in later.)
• Weed often. Dahlias have surface roots, and will suffer stunting from weed competition, so keep them weed-free during the first couple of months (later, they should shade out competition). Weeds also shelter slugs, snails, earwigs, sowbugs and other pests that can damage the young sprouts of your dahlias; you may need to use slug preparations like Sluggo at frequent intervals.
• Water only when needed. Unless your region is very hot and dry, don't water dahlias until they begin to bloom; then give the soil a good soaking every week (more often if weather is hot and breezy).
Stay tuned. We'll issue another bulletin when the plants at the farm are up.