Growing Baptisia australis from Seed

Home » Blog » Growing Baptisia australis from Seed

Robert Pavlis

Baptisia australis (fasle indigo) is known to be difficult to grow seedlings. Several sources report that plants die during the transplanting and subsequent maturation process. Today’s post reports on my success rate for maturing these seedlings.

In a previous post I reported on a research project to determine the Best Way to Germinate Baptisia australis Seeds.

germination of baptisia australis seed
Germination of baptisia australis seed

Germination of Baptisia australis Seed

The seeds were germinated in Ziploc snack bags containing some moistened paper towel. The seeds are quite large and it’s easy to see when a seed germinates. Such seeds were removed with tweezers and potted up in Pro-Mix soil, placing 1 to 4 seeds per 4 inch pot. If seeds are transferred as soon as the root radical appears, the success rate is usually quite high. Once a longer root is formed there is a higher risk that you damage the root during the transfer process. In cases were I have lots of seed, I will plant several in each pot, ensuring that I get at least 1 plant per pot.

Note: the seedlings in the picture are not B. australis, but both look very similar. The seedlings were left to grow a long root for demonstration purposes. I normally remove the seed long before the root gets this big.

Potted Seedlings

The pots containing blue indigo are kept fairly wet and in 100% humidity by keeping them in a covered container with some water in the bottom. Once the seedlings show themselves above the soil line the humidity and water are slowly reduced so that the seedlings get used to room conditions. When outdoor temperatures are high enough at night (over 8 deg C), the plants are slowly moved outside and conditioned to full sun.

Transplanting Seedlings

The pots are watered almost daily for a couple of weeks. I then transfer the seedlings into a pot containing local soil making sure that the roots are disturbed as little as possible. The pots now contain 1 or 2 seedlings each. Experience has shown that with most plant varieties, 2 seedlings per pot will result in at least 1 full size plant. The pots are  then dug in the ground so that the soil level inside the pot is at about the same level as the ground soil. The benefit of sinking the pots in the ground is that they stay wet much longer and the roots stay cooler. Instead of needing water every day, they can be left for 4 or 5 days between watering.

End of Summer Results

It is now early September and the Baptisia seedlings from this past spring are doing fairly well. Fourteen pots out of 20 have at least 1 plant in them. That rate is a bit lower than my average for various seed types, but it is fairly good.

Normally, the seedlings will remain in their pots, in the ground, until spring. In this case I have been growing them for a naturalistic planting project and they were picked up in late fall for planting in the field.

I kept a few seedling pots for myself, and left them in the ground over winter. Most were doing fine in spring.

 

If you like this post, please share .......

Robert Pavlis

I have been gardening my whole life and have a science background. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

12 thoughts on “Growing Baptisia australis from Seed”

  1. Hi Robert, and thank you for brilliant advice regarding growing Baptisia. Question: When you put two seedlings in a big pot over winter. If both make it, do you split them, or can they grow well together, as one in their final destination? I got lucky and ended up with 32 seedlings, pondering how to make the best out of them all.

    Reply
  2. In the spring of 2015, I scattered baptisia seeds in a flat, in some permutation of potting soil, and they germinated. I potted each in its own pot. Some survived 2016 and have sprouted in this spring of 2017 (the success rate is low, but I feel somewhat relieved I hearing that that is not unusual). So far, all have been puny. They were seeds from the two cultivars I happened to come across: ‘Screaming Yellow’ and ‘Electric Blue’. I hope their growth picks up this year. I wonder, will the seeds revert to the purple-blue of the species, or will they retain their yellow and blue of their respective parent plants (that were isolated from other baptisias)? I like the species, so it won’t be a disappointment if my plants bloom purple, but I’m curious.

    Reply
    • Since the two parents you used are hybrids, the seedlings will likely be different. How different and how much they look like the species depends entirely on their genetics. You have to wait and see.

      Reply
  3. I have found that scarification and nicking the seed coat and a soak in hot water did help seeds germinate, but there is a considerable propensity to die off even after it looks like plants are pretty well established. Here (Kincardine, Ontario) they seem prone to various sorts of fungal and insect pests that leave them alive, but barely. Currently, I have a few hopefuls that are battling the elements, some in the garden and some in pots, destined for my wife’s spinning friends (it is a traditional source of blue dye, which is really why I wanted to grow it in the first place). We’ll see if they make it through the winter; I’ve had others that didn’t; it reminds me of a similar situation I have had with trying to grow astragalus neglectus, which grows not far from here, but I now know needs a fungus helper to thrive. Do you think that there might be a similar symbiotic relationship here? I’m not aware of one.
    Tim Broughton

    Reply
  4. Robert,
    I have had good success with Baptisia seeds over the last two seasons with a roughly 80% germination rate this spring. To do this, I collected the seeds in fall, stored them dry in the refrigerator until November. I live in Manassas, VA and have found that seeds supposedly needing stratification will often germinate in the fall and be winter killed if planted too early. In November, place the seeds between two pieces of 120 grit sand paper and sand them until dull with an obviously abraided outer seed coat. After sanding, place them in a cup, pour in boiling water, add a drop or two of dish detergent and let them soak 24 hours. I THINK the detergent helps moisture penetrate the seed coat. Next, plant them in a well draining seed mix. I use seed trays and place the trays outdoors for the winter unprotected from cold. If the mix is not fine and well draining, frost heave can be a problem. Screens help keep varmints out and rain drops from splashing the seed mix away. This process has worked well with Senna marilandica and Tephrosia virginiana as well as baptisia. After germination, they can be thinned and up potted for good root development.

    Reply

Leave a Comment