Sunday, July 19, 2020

Apex again: It was a dark and stormy day...

Eriogonum ovalifolium
 I always wanted to start a post with that cliche! It WAS dark and stormy--hence the moody shots I took: and not too many because the sky did open up and rain. I have gone on and on about this garden in other blogs (just type Prairiebreak and APEX and they'll pop up--you can use Google as well as I can). It took Kenton Seth and Paul Spriggs a few weeks to knock this garden together with a handful of staff and volunteers, and Kenton's come back a handful of times over the last decade and probably spent a few hours each visit...or less. And the dang garden coasts on with benign neglect! Oh yes--this is one of a half dozen subspecies of E. ovalifolium: the others had shed their seed and this was still blooming in early July! They go from strength to strength here, and in other gardens melt away. Like mine!

Midsummer medley
 Eriogonum umbellatum var. porteri in foreground--already shed seed. The reddish spot in the middle is Jovibarba heuffellii (Also classed as a Semperivivum): much tougher and more drought tolerant than other hens and chicks. The silvery mat above it is Sphaeromeria capitata, common throughout the Wyoming steppe and barely sneaking into Colorado And we'll revisit the powderpuffs on the left shortly...and don't miss the paintbrush on the right--more on that too soon.

Teucrium subspinosum
 I first obtained this from Siskiyou Rare Plant Nursery (the only place that sold it) decades ago and we had some pretty good clumps in the Rock Alpine Garden. They'd often freeze back--it is from the Balearic islands after all, has to be tender don't you know!? It dies the first winter in most of our gardens. Kenton planted quite a few all over Apex and they just get better each year--and none have died: it obviously needs a crevice garden with sand to thrive on our harsh steppe.

Teucrium subspinosum
 The flowers are not showstoppers--but pleasant. And it blooms for months. It is attractive to cats--which fortunately don't seem to come to Apex: the spiny tips of the stems must give and S&M tinge to their catnip fix.

Scabiosa graminfolium
 A superb form of the grass-leaf Scabious. Blooms non stop for months and the seedheads are lovely.

Eriogonum wrightii v subscaposum
 Lots of this dotted around--each one looks a little different, and some definitely more E. kennedyi than this.
Castilleja integra
The paintbrush are self sowing! And they are living for quite a few years (we grow this one, but in ordinary rock gardens it disappears after a year or two.

Castilleja integra
 Look at this monster--blooming since April!

Acantholimon cf acerosum
 And there are quite a few spikethrifts in the garden, several waiting to bloom till now.

Acantholimon spp.
 The acantnolimons in this garden love it! And are self sowing as well...

Heuchera pulchella (left( and Arenaria alfacarensis (right)
 There are many plants of the Heuchera, all thriving and all different sizes. The Arenaria is a darlng, don't you agree?
Pterocephalus depressus
 There are numerous mats of this all over the garden, all covered with seedheads and bloom.

Midsummer is usually a slow time in the garden, but not at APEX!


  1. Last fall, I purchased an Arenaria alfacarensis and planted it near the top of my small crevice garden. It survived the winter fine and was doing well in spring. When the temperature got above 90+ degrees Fahrenheit most of the plant died except for an edge by a seedling I had planted which I had been laboriously giving regular misting. The same thing happened to my Arenaria 'Wallowa Mountains,' but this species did slightly better. I have since been misting both these Arenaria a few times during the hottest part of each day if the temperature is 90+ degrees F. I know it gets over 90 degrees F in Denver. I am sure the Apex crevice garden does not have a misting system. These Arenaria are supposed to be drought tolerant, so I know a lack of water is not the problem. I water the garden if it is dry. So, what is the secret for growing these plants in the heat? I see the Heuchera pulchella next to the Arenaria alfacarensis in your photo. Is the Arenaria alfacarensis planted on the north side of rocks where it is shaded from the mid-day heat? If I can't find a place where they will grow, I will have to give up on my Arenarias because I won't be able to mist them during hot days forever.

  2. I think situating them with shade during the hottest part of the day for you will solve much of the problem: I am wondering if they even water at APEX at all after my last few visits! I'd not water them in the heat of the day--only early morning or evenings. I have not found A. alfacarensis to be the easiest to grow--but 'Wallowa mountains' is tough as nails--I've seen huge specimens all over the country of that!

    1. It is difficult for me to find a spot that is shaded during the hottest part of the day, but still receives morning and evening sun. Generally, such a location is on the north side of a tree. As the tree grows, the location gets progressively more shade. Also, roots become an issue.

      My Aquilegia jonesii would always abort its blooms because of a late spring/early summer heat wave. I moved my last one to a spot that had full sun until the trees leafed out and then had dappled shade. The A. jonesii did well for at least a year and then died. It possibly did not have enough sun. Although other plants like Delosperma, Saxifraga, and Primula seem to be doing well enough in the location for at least this season.

      Maybe if I had watered more often, my Arenarias would have done better. I think it is really advantageous to have an irrigation system for a rock garden in more interior areas of the continent. I will try moving the A. alfacarensis and A. "Wallowa Mountains" because otherwise I know I will neglect watering them at some point and surly lose them. Putting them in a shadier location is my best chance.

      I did plant them in Turface, which seems to hold water a little better than sand yet still is free draining. However, if I let the Turface dry out it becomes a brick oven in the heat and sun. Only the most heat tolerant plants seem to be able to tolerate growing in this medium if I don't water at least once a day during the hottest driest days of the year. Maybe I should mix in some coir to hold water in the soil for longer so the plants can benefit from evaporative cooling for at least a full day before watering must be done again.

      Another species I seem to be having a problem growing in the heat is Astragalus whitneyi. I thought it could handle heat since it lives in northern Nevada. However, even with misting at least once a day, and often more if it is really hot, all my A. whitneyi seem to be suffering. In contrast, the Colorado native Astragalus sericoleucus is handling the heat just fine. As the climate warms, rock gardeners in the north might have to be turning to species from Colorado which can survive all the challenges of heat, cold, and drought.


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