Sowing Perennial Seeds

With the arrival of February and warmer temperatures, I've been sowing seeds in earnest this week, perennials in particular.  Seeds purchased or collected last year have the chance to sprout.  My goal is to get them started for easy propagation in years to come for planting prairies here at the house.  

Two species that I've had stratifying—a cool moist period to enhance germination in some species—in the refrigerator are Asclepias tuberosa 'Wild Orange' and Echinacea sanguinea.  I've checked on them weekly in the little baggies by opening the moist paper towels and inspecting them.  It's a nice way to also introduce some fresh air in the sealed vessels since seeds need oxygen for germination.  For the Asclepias, I noticed swelling in the seeds and some rupturing of the seed coat, a clear indication they were ready for planting.  The Echinacea seed held onto their dingy off-white color while the other detritus from the seed head turned black.  

Plump  Asclepias tuberosa  seeds. Seed the tinge of light yellow? The seed coat has ruptured on one near the center.

Plump Asclepias tuberosa seeds. Seed the tinge of light yellow? The seed coat has ruptured on one near the center.

Echinacea sanguinea  seed were mixed in with parts of the flower head. I decided to stratify them together and pull the seeds out when sowing.

Echinacea sanguinea seed were mixed in with parts of the flower head. I decided to stratify them together and pull the seeds out when sowing.

These made their way into seed trays earlier this week.  With the Asclepias I was sure to sow the seeds in a tray deep enough (approximately 5–6 inches) to allow their roots to grow down.  Allen Bush shared with me that shallow trays can cause their demise because the root doesn't have enough room to grow down.  

Along with the seeds that have been chilling in the fridge, I also scarified some seed this week and allowed them to soak for a couple of nights to prep for planting.  Scarification damages the seed coat and allows water to enter.

Last August, I collected some Baptisia sphaerocarpa seed from a location I saw it blooming several years prior.  Fingernail clippers make quick work breaking the seed coat on a few seeds.  

A few roots began to appear on  Baptisia sphaerocarpa .

A few roots began to appear on Baptisia sphaerocarpa.

Another species that I scarified was Amsonia tabernaemontana.  The seed came from my dad.  Years ago, I found an Amsonia blooming on the roadside near home.  The fear that it would succumb to the mower or herbicide like I had witnessed happen to many other plants inspired me to relocate the clump to our yard.  It settled in nicely and started producing seed.  A year or two ago, I asked my dad to collect any fruit he saw, and that Christmas I returned home to find the baggie on the windowsill.  Now that I have a house of my own, I felt it time to try growing the northern provenance here.  The germination requirements were unknown to me; however, from a quick google search, I discovered researchers at UGA demonstrated that clipping the end of the seed would allow moisture in to kickstart the germination process.  

Amsonia tabernaemontana  seedlings emerged from an intriguing cigar-shaped seed. With the embryos popping out, they look like    sea tube worms   .

Amsonia tabernaemontana seedlings emerged from an intriguing cigar-shaped seed. With the embryos popping out, they look like sea tube worms.

Today the seeds are in the garage instead of their cold frame.  The forecast showed below freezing last night, and I didn't want to take any chances since I've worked hard to get them all started.  Here’s to hoping they all germinate!




Natural Grafts

One of the questions I get about grafting is how in the world did people discover that you could take two different plants and combine their disparate tissues together?  

I think people of old knew grafting was possible because they had seen plant tissues recombine in nature.  Naturalists were outside surveying their environment, and from what they learned from nature, they applied that knowledge to grow plants better.  


We have a massive chinquapin oak (Quercus muehlenbergii) in our front yard in Tennessee.  A few years ago, I noticed for the first time in our thirty years of living there that it has a natural graft on the back side.  It is more unusual than most that I’ve seen because three branches come together.  

The winter frame of chinquapin oak

The winter frame of chinquapin oak

 
Thread this needle. On the back side of the tree is this natural graft where three branches have become one.

Thread this needle. On the back side of the tree is this natural graft where three branches have become one.

 
Here’s a side shot. You can see a branch behind curve up and down to merge with the other two branches.

Here’s a side shot. You can see a branch behind curve up and down to merge with the other two branches.

These natural grafts have been known to occur for a long time.  This bulletin from Kew printed in 1917 (over 100 years ago!) describes the process well.  Branches rub off the outer bark in the wind, callus (wound) tissue forms, and eventually the tissues on the two limbs grow and conjoin together.  It is so fascinating to think about the process of how the vascular tissues of large branches can realign and to witness the products of a years-long process.