Caesalpinia seeds

[Stephen Tashi]

Main Question or Discussion Point

Sellers of seeds of the Bird of Paradise tree say to scarify or nick the seeds before planting them. How hard or gently should this be done?
https://www.adeniumstore.com/seed-germination-c-104/caesalpinia-seed-germination-growing-guide-p-1383.html

Is there a natural process that implements the scarifying?

I collect seeds from the trees in a friend's yard. There are lots of empty twisted pods on the ground. Is this twisted shape typical of how seed pods open?

 

[jim mcnamara]

Opening - moisture changes and drying cause uneven pressure on the suture (the line on the fruit (seed pod) where the split happens)

Hard seed - many legumes like bird of paradise and alfalfa (pea family, fabaceae) have hard seeds. The seeds have to be stratified and/or be scarified to germinate - allow water to penetrate the outer seed coating - the testa - which is initially very resistant to water absorption.

Stratification is exposure to drying and wetting cycles, cold/frost is also often part of the deal.
Scarification occurs with moisture/cold cycling and microbial breakdown of the testa.

Scarification with sandpaper works well. Get a piece of fine grit paper, a small wide mouth jar with a lid, like a baby food jar. Cut the paper to fit inside the jar. What you want is to make a "second" interior wall lining with sandpaper - grit on the inside. This isn't a precision thing. Put the seeds in the jar, put on the cover, and shake. Because I used to do lots of seeds I used a Quaker oats cylindrical paper container. Seed houses have equipment that looks like a small potato polisher with very fine teeth. See video below

Try for about 5 minutes of agitation.

Before you plant, soak the scarified seeds for at least 24 hours. Any seeds that do not "puff up" need another dose of the sandpaper treatment.

PS: how well the plants grow is a function of the water they get until they have a decent root system. Water twice a week for the first few months.
Massive operation:


Small tabletop to potato polisher

https://www.webstaurantstore.com/22-lb-potato-peeler-110v/915DB10.html

 

[Stephen Tashi]

I had several caesalpina seed pods sitting in the console of van between the front seats. Today I found the twisted halves of one the pods on the floor of the car and seeds were scattered about. Perhaps when these pods burst open, they fling their seeds.

 

[jim mcnamara]

That is exactly what they do. Dehiscent pods like that can fling seeds a good distance.

Botanists, IMO, got a bit overzealous categorizing: https://en.wikipedia.org/wiki/Dehiscence_(botany)

Discussion and a model of "exploding" seed pods (fruits): https://www.mpg.de/10546404/seed-dispersal