Lignum Vitae
Blue flowers, the densest wood on earth, and about an inch of growth a year
Guaiacum sanctum
Photo: Longleaf Design
Why it works here
Lignum vitae means wood of life, and this is one of the great trees of the Caribbean. Blue to purple flowers come on and off all year with a spring peak, followed by orange yellow capsules that split open to show seeds in bright red coats, and the mockingbirds and catbirds go after those. It is the larval host for the lyside sulphur butterfly. The wood is so dense it sinks in water, which is why it got harvested for centuries and why it is now state listed endangered in Florida, with wild plants only in Miami-Dade and the Keys. The form is gnarled and irregular and slow and beautiful. And that brings me to the honest part, which is the whole story with this tree: FNPS documents it growing as little as an inch a year after the seedling stage. There is a specimen at the Key West Garden Club that is about 20 ft tall and estimated at over 150 years old. You are not planting a shade tree. You are planting an heirloom.
Care
Plant high, in well drained soil, and do not overwater it. That is most of it. Light feeding does appear to speed it up somewhat, since the inch a year figure is specifically for an unfertilized plant, so an annual topdressing of compost is the one place you can legitimately buy a little speed. UF says it has no pests or diseases of concern, and that has been true for me.
Common problems
The growth rate, which is not really a problem so much as the defining fact. If you want a lignum vitae with presence, you buy it at size, and the price curve is steep for exactly that reason.
Overwatering. It wants sharp drainage and it will rot in a wet pocket or an irrigated bed.
Cold. UF rates it 10b and up while FNPS says 9b and up, which tells you nobody is certain. We are on the seam. Give it a warm, protected spot and you should be fine.
Buying the wrong plant. Guaiacum officinale and the trade wood called verawood get sold under the same name. Check the tag for Guaiacum sanctum.
Common questions
How fast will it grow?
About an inch a year unfed. I know that sounds like I am talking you out of it. I am not, I just refuse to let somebody spend this kind of money expecting a tree.
Why is it so expensive?
Because you are buying nursery time. Every year that tree sat in a pot is in the price, and it sat there for a lot of years. A small one is genuinely cheap. A specimen is not.
Will I actually see the blue flowers?
Yes, but after it settles in for a few years, and it flowers sporadically through the year rather than all at once. When it goes, it is one of the few true blues you will ever get from a tree in Florida.
Interested in a lignum vitae in your landscape?
We plan, install, and care for it. Start with a paid consultation.