The pencil marks climb the back fence in my Zone 10a Southern California yard, one above the next, a hand's width apart. I planted the grafted jacaranda as a knee-high whip. I added those marks across a single warm season while it pushed up several feet of fresh wood. That is how fast jacarandas grow in a frost-free climate. The jacaranda growth rate is fast, and in warm weather a young tree can gain up to 10 feet (3 meters) of height in one year.
The jacaranda growth rate hangs on heat. A jacaranda is a heat-driven grower, so it races ahead through warm summers and stalls where the air stays cool. NC State Extension rates the tree a fast grower, but that rating assumes real warmth. Plant one in a cool coastal spot or a marginal zone and you'll see far less than 10 feet (3 meters) a year. Give your tree long, hot summers and it stretches toward that number. In its warm native range across South America, this pace is normal for a young tree.
Growth runs fastest while the tree is young. A sapling pours its energy into shooting upward, so you get the biggest jumps in height in those early years. Your young tree can pass head height within a couple of warm seasons and clear a single-story roofline within several years. As the tree matures, the upward pace eases. It puts its energy into a wide canopy and its first flowers instead.
Fast growth carries a couple of trade-offs for you. The quick wood is soft and a bit brittle, so young branches can snap in a strong wind. A hard frost sets your tree back as well, since jacarandas are tender and drop fresh growth when the cold bites. In a cool or frost-prone zone, expect the slow end of the range and some winter damage.
Height and flowers run on two separate clocks. A jacaranda can shoot up fast and still hold off on blooming for years. You may wonder about the years to bloom jacaranda trees need, and the answer comes down to how each tree got its start. A seed-grown tree often stays green and flowerless for 7 to 14 years, and sometimes longer. A grafted or cutting-grown tree already carries mature wood, so it flowers within a few years of planting. Either way, your tree settles at a mature height of 25 to 40 feet (7.6 to 12 meters).
The reason comes down to the wood itself. A cutting or graft is taken from a tree already old enough to flower, so it keeps that blooming age even on a small young plant. A seedling has to grow all the way to maturity on its own before it can bloom. That gap is why two jacarandas the same height can look nothing alike in your yard, with one full of purple bloom and the other still bare.
If you want purple flowers within a few years, buy a grafted or cutting-grown jacaranda rather than one raised from seed. Ask the nursery how your tree was propagated before you pay, since the answer sets how long you wait for color. Then plant it in full sun, because shade slows the growth and cuts the number of blooms. Water your young tree well through its first summers to fuel that fast climb, and give it room, since the canopy spreads wide with age.
The jacaranda growth rate has two halves. Height comes fast at up to 10 feet (3 meters) a year in warmth, and flowers come fast only if you skip seed and start with a grafted tree in full sun.
Read the full article: Jacaranda Tree: Complete Care and Growing Guide
