Eastern Redbud

Site and soil

Redbud is an understory tree by nature, so it will take more shade than most fruit and nut trees will. Illinois Extension notes that redbuds grow best in full sun but tolerate partial shade, with flowering reduced, and that they handle a wide range of soils as long as those soils are well drained. Clemson Extension adds that redbud does well in most soil types and tolerates acid or alkaline soils, but dislikes permanently wet areas. The short version: plant it anywhere water does not stand.

This tree is hardy in USDA zones 4 through 9. It wants medium to fine textured soil at a pH between 5.0 and 7.9, full sun to partial shade, and little water once it is settled in. Good spots on a hill farm are a forest edge, an east facing slope, or the second story under taller canopy trees.

Spacing

Mature height runs up to about 30 feet. NC State Extension gives a mature spread of 20 to 35 feet wide; Clemson Extension gives 15 to 35 feet. The 6 to 12 foot spacing on this listing is for close rows, hedgerows, and alley plantings where you want the canopies to knit together into a flowering understory line. For one tree carrying a full rounded crown, allow 20 feet or more of open ground.

Planting

Plant it where you mean to keep it. Clemson Extension advises transplanting redbuds when they are very small, because they have difficulty surviving a move once the root system has developed. Pick the spot once and commit to it.

• Dig the hole about as deep as the root ball and two to three times as wide, loosening the sides so new roots can push out into the native soil.
• Set the tree so the root flare, the point where the roots begin to spread away from the trunk, sits level with the surrounding ground. WVU Extension is firm on this: the flare should be level with the original soil level.
• Backfill with the soil you dug out. WVU Extension allows 20 to 30 percent compost or aged wood chips mixed into that original soil, and nothing more exotic than that.
• Water slowly as you backfill, to settle the soil and close the air pockets around the roots.
• Spread 3 to 4 inches of mulch over the root zone, then pull it back off the bark at the base of the trunk. WVU Extension warns that mulch piled against the trunk invites collar rot, root rot, winter injury, and insect and rodent damage.

First-year care

The first season is about roots, not top growth. Water deeply once a week through the first summer, more often in sandy ground or a long dry spell, and let the top inch of soil dry between waterings. Clemson Extension notes that redbuds tolerate moderate dry spells but do better when irrigated in summer dry spells, and that holds doubly true in year one.

Keep the mulch ring wide and the grass out of it; turf pulls water from the same few inches of soil the young roots are working. Illinois Extension reports that redbuds grow moderately fast when young, reaching 7 to 10 feet tall in five to six years, and then slow as they mature. So most of what year one buys you is a thicker stem and a better root system rather than visible height.

Pruning

Redbud needs very little pruning. Take out broken, rubbing, or dead wood, and lift the lowest branches only where the tree sits near a path or a patio, which is the one case Clemson Extension calls for: low branches must be pruned for clearance beneath the canopy.

Two rules matter more than shape:

• Prune in dry weather. Clemson Extension advises pruning during dry conditions. The disease it has in mind is Botryosphaeria canker, which causes branch dieback, and Clemson is blunt that there are no fungicides to control it.
• Cut well below damage. Where you find a sunken, cracked, or diseased area on a stem, Clemson Extension says to cut the stem 6 to 8 inches below that area rather than trimming back to the edge of it.

Go easy on the old limbs. Illinois Extension points out that redbud flowers develop in clusters along the branches and even occasionally on the trunks of trees, a habit called cauliflory, so the mature wood you remove is the wood that blooms. Watch for Verticillium wilt and Botryosphaeria canker as the tree ages; Maryland Extension and Illinois Extension both name them as the species' main troubles, and Illinois notes that healthy trees often live 50 to 75 years while stressed or infected ones fall well short.

Harvest

There are two harvests here, and neither is a fruit crop in the ordinary sense.

The flowers come first, ahead of the leaves, and they are edible. Illinois Extension puts it plainly: the flowers of redbuds are also edible, and can be eaten fresh, where they taste similar to peas, added as a garnish to salads, pickled, fried, and used to make jelly. They open as early as any tree on the place and last several weeks, which gives you a long picking window in spring. Pick lightly from a young tree and leave the bulk of the bloom to the insects. Illinois Extension notes that because redbuds bloom so early they are an important food source for early-season pollinators such as bumble bees and carpenter bees, weeks before the rest of the orchard wakes up.

Flat seedpods follow, turning from green to brown through summer and fall. Maryland Extension notes that northern cardinals and other songbirds eat the seeds. If you want to raise more redbuds from your own pods, the USDA Forest Service reports that in nursery practice both scarification and cold, moist stratification are required for germination; seed sown straight out of the pod will simply sit.

On timing, expect a few years before the first pods. The USDA Forest Service reports that pods may be borne by a 5-year-old eastern redbud, that first reproduction on average comes when a tree is about 15 feet tall, and that good seed crops usually occur in alternate years. Pollination is not something you have to plan around: Maryland Extension describes redbud flowers as self-pollinating and insect-pollinated, so a single tree will set pods on its own. A second tree is for your own pleasure and for the bees, not for fertility.