I'm not one to question Mother Nature's good intentions, but have you ever wondered how she arrived at some of her rules? An uncharitable person might suggest some of her confusing laws of nature were formulated after a night on the town.
Why, for example, is it best to plant tomatoes deeply, burying the stems, but if you do the same with pepper plants, tomato's close cousins, the stems rot?
Mastering how deeply to plant is perhaps gardening's most basic secret of success.
The following demonstrate how varied the rules of planting depth can be.
- Spread grass seed on the soil surface and rake lightly, leaving most of the seed exposed.
- If planted properly, seed should still be visible.
- Situate trees so the trunk flare, the widened portion between trunk and roots, is visible after planting.
- Many trees are planted too deeply, causing a slow and often undiagnosed tree decline five to 20 years in the future.
- Most are grafted. Look for the knobby joint on the lower trunk where the top variety was spliced onto the rootstock.
- Locate the graft knob above ground, with the tree's trunk flare visible, as described when planting trees.
- For potted shrubs, after slipping out of the pot, plant deeply enough so that your soil just barely covers the root ball soil. If the rootball is exposed from too-shallow planting, water will 'wick' away, dehydrating the roots.
- Plant bare-root shrubs so the 'crown,' the junction between branches and roots, is at soil level.
- Deep planting of roses is important for winter survival.
- Locate the crown (junction between branches and roots) three to four inches below soil surface.
- Plant most potted perennials at the same depth as planted in the pot, just barely covering the rootball with flowerbed soil.
- Proper peony depth is vital. Plant with the uppermost 'eye,' which are the pink, red or white buds visible in the roots, one-and-one-half inches below soil surface.
- Plant at the same depth as in the pot or pack, or just slightly deeper.
- Firm soil around rootball for important soil-to-root contact.
- Depth must be precise for best growth.
- Plant with the central crown (spot where stems meet roots) directly at soil level, not too high, and not buried deeply.
- Cover fine, small seed like lettuce and carrot with one-fourth inch of soil, which is just barely covered.
- Seeds that are slightly larger, like radish, beet, spinach and kale are planted slightly deeper, covered with one-half inch of soil.
- Large seeds, like pumpkin, squash, cucumber, melon, corn, peas and beans are planted about one inch deep.
- Plant seed potato pieces or egg-sized whole tubers three inches deep, onion sets one inch deep.
- Tamp down soil lightly after planting with the flat side of a hoe.
- Remove lowest leaves from tomato transplants, and plant deeply, burying the stem up to the remaining leaves. Tomato plants root along the buried stems, creating stronger plants.
- Peppers don't tolerate deep planting. Just slightly cover the rootball with garden soil.
- Cabbage, cauliflower and broccoli can be planted slightly deeper, covering the rootball and part of the stem, so plants aren't weak and wobbly.
Don Kinzler, a lifelong gardener, worked as an NDSU Extension horticulturist and owned Kinzler's Greenhouse in Fargo. Readers can reach him at email@example.com.
He also blogs at growingtogether.areavoices.com.