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Monday - April 04, 2011

From: Austin, TX
Region: Southwest
Topic: Poisonous Plants, Shrubs
Title: Failure to bloom of Eve's necklacepod in Austin
Answered by: Barbara Medford


I have a young Eve's necklace that never blooms in the spring. I wonder every spring if this will be the year, but the blooms never come. Is there a reason for this? The tree is about three or four years old, is now about 5' tall. It gets great morning sun, but afternoon shade. It is planted in well draining soil, probably alkaline. Fairly near to this tree we planted--in the same soil--two Mexican Buckeyes that bloomed their first year. I am not sure if this tree has a gender, or if I need to fertilize or what. Thanks!


When we are asked a question we don't know the answer to, we always start with the basics first. That is usually "is this a plant that belongs where it is being grown?" The Lady Bird Johnson Wildflower Center is dedicated to the growth, protection and propagation of plants native not only to North America but to the area in which the plants are being grown. According to this USDA Plant Profile Map, Styphnolobium affine (Eve's necklace) does indeed grow in Travis County, so it's in the right place, and probably the right soil.

So, next, is it getting the right amount of sun? According to the webpage in our Native Plant Database, this plant requires part shade, which we consider to be 2 to 6 hours of sun a day. Most blooming plants do need a good deal of sunlight in order to bloom well, but it sounds like you have the right amount of sun, too.

Also from that plant page: "The planting site must be well-drained or it will get chlorotic." That means that the leaves are not getting enough manganese and iron from the soil to create chlorophyll, usually because of poor drainage or root damage. We can't see that this should affect the blooming, unless the health of the whole plant has been compromised. Another possibility might be the fertilizer you are using. If the plant sits in a grassy area that is fertilized, it might be getting too much nitrogen. Lawn fertilizers are high nitrogen, to encourage lots of green leaves, which is what lawn grass is. On the other hand, if a plant is working hard to create all the leaves the nitrogen is inspiring, it may run out of the vigor to produce blooms, too. Most native plants do not need fertilizing if they are being grown under the right conditions, and this plant particularly does not like fertilizer.

So far, we are batting 000 here. Next, we'll go online. The first article we found is from Landscape Mafia.com. Next, The Dirt Doctor. We are trying, honest, but we are just not finding anything about the age at which this plant blooms. Native Plant Society of Texas.

Okay-UNCLE! We are not usually totally stumped, but we can simply find no information on whether your plant is old enough to bloom. We suspect that this is because there has been no scientific study on this plant related to its development. If you are satisfied that you are providing all the other necessary conditions for this plant to thrive, we suggest you be patient another year or so. On the bright side: the flowers and seeds of this plant are poisonous.

From our Native Plant Image Gallery:

Styphnolobium affine

Styphnolobium affine

Styphnolobium affine

Styphnolobium affine




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