Germinating Desert Seeds / Recognizing Friend and Foe in the Yard

It's November in Phoenix and plants are already beginning to sprout from seed in the yard. Are they keepers or candidates for removal? It can be difficult to tell because juvenile plants don't always resemble more mature specimens. So by germinating the seeds we'll hopefully learn to recognize the seedlings that sprout in the yard.

We have a new landscape, and there are plants that I have cultivated throughout the yard by spreading seeds. Examples include:

Desert (or Rush) Milkweed, Asclepias subulata
Damianita, Chrysactinia Mexicana
Parry's Penstemon, Penstemon parryi
Wooly Butterfly Bush, Buddleja marrubiifolia
Angelita Daisy, Tetraneuris acaulis

Planting Seeds

I'm using an Aero Garden to germinate the seeds, but a simple seed-starter mix or peat pods work just fine. I don't know if any of the seeds have special requirements, like scarification, light/dark germination or minimum cold hours. We're also going to learn how long it takes for some of these seeds to sprout.

11/20/2020 Setting Up the AeroGrow and Planting Seeds

11/23 One cell of Asclepias subulata has sprouted

11/24 Two cells of Asclepias subulata have now sprouted

11/24 What's germinated in the yard?

I posted these observations of seedlings in the yard on iNaturalist - perhaps someone can help ID them!

?? Dicots, Maybe a young Mirabilis laevis villosa?
?? Sunflowers, Daisies, Asters, and Allies Family Asteraceae
??Dicots
??Sow Thistles Genus Sonchus
Likely a Caesalpinia mexicana

11/25 Rush Milkweed dicot update

11/26 Rush Milkweed update

11/29 Rush Milkweed update

11/30 Asclepias First True Leaves

12/1 Progress Update

So far only the Asclepias subulatas have germinated. I'm not sure if there are issues with the other seeds, or if they just take longer to germinate; time will tell! Room temperature is 75 degrees, which may be a bit cool for some seeds.
An interesting point to note though - all of the Asclepias subulata seeds did not germinate at the same time. The first to germinate actually turned out to be a weak sprout and has since died. And today one of the seeds is just starting to germinate. Nature purposely staggers germination to ensure that some plants will grow even if conditions take a temporary turn for the worse.

12/1 Added a Heater to the Water Reservoir

I added a small aquarium heater (Beta fish tank thermometer, no thermostat) to the water reservoir to boost the temperature into the mid-upper 80s; the water temperature has been around 72 at night and 76 during the day. The thermometer reads low by about 7.5 degrees F (not uncommon with very inexpensive thermometers)...

Heater Change

The Beta tank heater is designed to keep aquarium water about 10-15 degrees F above ambient. However, this reservoir has a styrofoam top, so water temperatures were into the 90s and still rising yesterday afternoon, so I switched it out for a small thermostatically controlled heater that keeps the water at about 78 degrees. Not as high as I wanted, but better than no heater; I'll continue to look at options.

12/2 Another Heater Change

Good thing I've been in the aquarium hobby for a few years and acquired a collection of spare heaters :-) Did a test in a small container of water using a small heater with a variable thermostat - this thermostat should keep the reservoir in the 84 degree range and hopefully inspire further seed germination!

Asclepias Update 12/2

Two of the seedlings are doing well, with one furthest back sprouting in earnest. What you can't see is the length of the roots, which are curiously long - I'd estimate 8" long for the more mature seedling!

12/5 Some Research on Propagation

While the Asclepias subulatas have done well, the other seeds have not yet germinated, so it's time for a bit of research to see what information is available about propagating the plants

Desert Marigold - Baileya multirada

According to wildflower.org, these seeds have low germination rates and require a moist chilling period to germinate. Given this information, we may not see any plants germinating in this batch.

Parry's Penstemon - Penstemon parryi

According to wildflower.org, germination is best with cold-moist stratification, a condition not met in the current planting. Seeds take about 21 days to germinate, so it's possible we might see some results yet, but a bit of time in the refrigerator would have helped.

Damianita - Chrysactinia mexicana

According to wildflower.org, seeds should be planted as early as possible, especially in fall. No cold stratification is mentioned. No germination times are provided. Seed does not store well; sow as soon as possible. We'll have to keep waiting and see on this one.

Angelita Daisy - Tetraneuris acasulis

It doesn't appear that these seeds need any special requirements, so we'll just have to wait and see

Wooly Butterfly Bush - Buddleha marrubiifolia

The information that I found all relates to propagating from a cutting, so starting from seed may not be a viable option; we'll wait and see.

Happy Asclepias subulata

Well, the Asclepias subulata are happy, but I'd say the other seeds will not be germinating, for whatever reason. I've germinated lots of seeds in the past with high success rates, so not sure what went wrong this time around. But I'll be looking for an opportunity to learn, and will probably restart some of the seeds down the road.

Asclepias subulata Planted

The Rush Milkweed were ready for transplanting, so I moved them into a cactus mix medium. The other seeds showed no signs of germination, and I confirmed no growth was imminent with a peat pod autopsy :-) Perhaps I'll try again in 2021...

1/21/21 Found a seedling photo of the Desert Marigold (Baileya multiradiata)

So now that plants of all types are starting to germinate, I'll be better able to determine "friend from foe."

Another Source for Seedling Images

Also found this Wildflower Yard web site that shows the seedling stage of a dozen or so wildflowers - what a great resource! Includes pics of Baby Blue Eyes, Blue-eyed Grass, California Poppy, California Desert Bluebells, Desert Marigold, Farewell to Spring, Fiddleneck, Five Spot, Golden Lupine, Sunflower, Tidy Tips and Yarrow.

Damianita Seedlings

1/27/2021 Rain, Finally!

We've had more than an inch of rain over the past couple of days, yay! An Arctic front brought in the rain, along with much cooler temperatures - nighttime temps have been in the mid-to-upper 30s - cold, with light frost, but fortunately I'm not seeing any frost damage. This precipitation should start a robust germination event, mostly unwanted plants (weeds :-) in the landscape, but time to be on the lookout for the plants that I sowed in the yard!

1/29/2021 Spotted in the Yard

Looks like a Rush Milkweed seed germinated early!

Posted on November 23, 2020 11:05 PM by pollinatorweb