Actual size and flowering may vary slightly based on season.
Ironwood
Desert ironwood is a Sonoran Desert native tree with gray-green leaves, a gnarled gray trunk and pink to lavender pea flowers in late spring. It grows into a 20 to 30 foot shade tree with enough medium shade to grow other plants beneath it. Bees and birds use it, and in the wild it shelters young plants and desert wildlife. Once it is rooted it gets by on little water.
Best for: native low-water shade, sheltering cactus and sun-tender plants beneath its canopy, and a desert yard that feeds bees and birds.
Ironwood grows into a 20 to 30 foot tree with a canopy of gray-green leaves. Once rooted it needs only a deep soak every 2 to 3 weeks in summer. Plant it 20 feet or more from other trees.
Its canopy casts enough medium shade to grow sun-tender plants underneath. Use it to shelter a cactus garden or other plants that scorch in full summer sun.
Pink to lavender pea flowers cover the tree from late April into May, and native bees and honeybees work them. Birds and other desert wildlife use it for food and cover.
Young trees are tender in a hard freeze, so cover them on the coldest nights. The branches carry sharp paired spines, so keep lower branches trimmed near paths. Growth is slow, especially on dry, rocky sites.
- Row or grove of trees20 ft apart
- Single shade tree20+ ft apart
Right after planting, soak it every 1 to 2 days in summer, or every 3 to 4 days in the cooler months. By the second month, aim for about once a week in summer, and keep regular deep soaks going for about 3 years. Once rooted it gets by on very little. Extra deep soaks at the canopy edge a few times a month in summer speed up its slow growth.
The nursery stake comes off at planting, and stakes go in only if the tree cannot hold itself up or wind is a problem. Two stakes outside the root ball, soft ties, and a little sway build a stronger trunk. Remove them in about a year.
Ironwood needs only light pruning. Remove dead wood and any low branches in the way, and clip lightly to keep a balanced shape. Do heavier cuts only in the cool months, so newly bared branches do not sunburn.
Temperatures around 20°F damage the leaves, and a long freeze can kill it. Cover a young tree with frost cloth on the coldest nights.
Drainage test first. Dig the hole and fill it with water. If water is still sitting in the hole a day later, you likely hit caliche, clay or hard soil, so fix the drainage before planting. If it drains very fast, the soil is sandy. Standing water around roots is a common reason new plants fail.
Weed cloth. Cut it away from the planting hole and where the roots will spread. Remove any plastic sheeting completely, since it keeps water and air out of the soil.
Rock or decomposed granite with no soil underneath. Bring in soil close in texture to your native soil, mix it with the soil below, and build up enough depth for roots before planting.
If you can break through. Use a breaker bar, pick, or jackhammer. Dig through the caliche and break out the solid chunks. Backfill with the soil you dug out, with no compost or manure in the hole. Confirm drainage before planting.
If you cannot break through. Dig narrow holes through the hard layer beside the root ball, not under it, and refill them with the same soil, not gravel. If it still will not drain, plant on a low mound of the same soil.
Root ball. Check the outside edges for any roots circling around. Loosen or cut those so they grow outward. Do not break up the center of the root ball.
Depth. The top of the root ball should sit at or just slightly above the surrounding soil level. Planting too deep can lead to rot and kill the plant.
Drip emitters. At planting, put the emitters on the root ball, on different sides of the plant. After about 2 months, move them to the outer edge of the root ball. Over the first year, add emitters farther out toward the edge of the branches as roots grow. Once a plant is rooted, never water only at the trunk.
How fast does desert ironwood grow?
Ironwood is a slow grower. A deep soak a few times a month in summer speeds it up, and it grows faster with low to moderate water than on rain alone.
How big does desert ironwood get?
In a yard it usually reaches 20 to 30 feet tall and about as wide. Plant it 20 feet or more from other trees and check the Spacing tab before you dig.
When does ironwood bloom?
It blooms from late April into May with pink to lavender pea flowers. Give it full sun for the best bloom and a healthy shape.
How often should I water an ironwood?
Water a new tree often while it roots in. Once established, give it a deep soak every 2 to 3 weeks in summer and about once a month in winter.
How cold hardy is ironwood in Phoenix?
Mature trees handle about 20°F, and young trees are more tender. Cover young trees with frost cloth on hard freeze nights, and wait until spring to trim any damage.
Does ironwood have thorns?
Yes. The branches carry sharp paired spines. Wear heavy gloves and long sleeves to prune, and trim lower branches away from paths as the tree grows.
How should I prune an ironwood?
Prune lightly, only to shape it and remove dead or low branches. Do bigger cuts in the cooler months, because newly exposed branches can sunburn in summer.
Is ironwood evergreen?
It keeps its leaves most of the year. In a hard freeze or a long drought it can drop some of them, then grows new leaves when conditions improve.
Is desert ironwood good for wildlife?
Yes. Bees visit the spring flowers, and birds and other desert wildlife use the tree for food and shelter. In the wild it acts as a nurse tree for young plants.
What soil does ironwood need?
It grows in most soils that drain well, from sand and gravel to loam and clay. Avoid low areas where water stands after a soak.
Is ironwood messy?
It drops some litter at certain times of the year. Plan on a few cleanups a year if it shades a patio or pool.
Ironwood for sale in Arizona, delivered to you
Desert ironwood is one of the signature trees of the Sonoran Desert. It gives medium shade on little water, blooms lavender in late spring and supports bees, birds and other wildlife. Below is what to expect in a Valley yard: size, growth, water, frost, pruning and spacing.
Sourced from trusted Arizona growers and delivered directly to your door, job site, or property. We deliver across the Valley and to nearby towns, and quote delivery anywhere else in Arizona.
How big does desert ironwood get in Phoenix?
In landscapes ironwood usually reaches 20 to 30 feet tall and about as wide. It grows slowly, so plant it for the long term and give it room.
How often to water a desert ironwood
Once established, a deep soak every 2 to 3 weeks in summer and about once a month in winter is plenty. A little extra summer water speeds its slow growth.
Ironwood frost protection
Mature ironwood handles about 20°F, and young trees are more tender. Cover young trees on hard freeze nights and trim any damage in spring.
When does ironwood bloom in Arizona?
Ironwood blooms from late April into May with pink to lavender pea flowers. Bees, including many native bees, visit the flowers.
Ironwood as a nurse tree
In the wild, ironwood shelters young plants and gives desert wildlife food and cover. In a yard, its medium shade can protect cactus and sun-tender plants below.
Pruning ironwood safely
Keep pruning light and do bigger cuts in the cooler months. Wear heavy gloves for the sharp spines, and remove low branches near paths as the tree grows.
How far apart to plant desert ironwood
Space ironwood trees about 20 feet apart or more. That leaves room for the canopy to spread to its full width.
We deliver across the Valley, from Phoenix, Scottsdale and Mesa out to San Tan Valley, Maricopa and Casa Grande, and up to Prescott, Sedona, Payson and Globe. See delivery areas and rates.