Ask Mr. Smarty Plants

This sounds like a very worthwhile project, and this member of the Mr. Smarty Plants team is familiar with the Jemez Mountain area in the Santa Fe National Forest, which is truly spectacular on its own. Obviously, you already know that there will be difficulties in planting at that elevation and have made the wise choice of using native annual seeds for the planting.

In terms of the boxes for these plants, while we think it is a good idea to set off each area with some kind of border, we would prefer that the roots went into the soil, not into planting mix above the ground. The reason for this is that, as you surely know, even in mid-summer it can get very cold at night where you are working. The best insulator is the Earth itself, and the less exposure the roots have to the cold, the better. The roots, which hold the moisture for the plant, are very vulnerable. If the cold is such that the water in those roots freezes, the plant will die, before it has had a chance to set seed for next year's display. We are not familiar with the soil you have, but assume it is pretty rocky. For that reason, we suggest digging out planting areas for the wildflowers and amending the soil with compost. As this compost continues to decompose, it will create more warmth for the seeds and then the roots that you plant in Spring.

Exposure in each direction really is not as important as the amount of sun available in the planting area, and the amount of sun each of your annuals requires. We will take some of your choices and check out the amount of sun they need. You can follow each plant link to the page on that plant in our Native Plant Database, and, of course, check any other native plant in that database.

Since there are often many plants identified by one common name, such as "penstemon," we checked for the color you mentioned, that the plant we selected grew in or near Sandoval County, and its light requirements. Of the ones we searched for, none were annuals, 1 was biennial and the others perennial. Perhaps you are planning to treat them all as annuals; if not, in order for them to survive over the winter, it will be even more important to have their roots deep in the soil, and that they be mulched in the Winter. All but one of the plants requires part shade (2 to 6 hours of sun a day) which may cause you some problems as you say the area is in an open grassland without trees.

 Penstemon strictus (Rocky mountain penstemon) - perennial subshrub, blooms blue, purple May and June, part shade. From our page on this plant: Native Habitat: Open, often rocky soil at moderate elevations.

Penstemon eatonii (Firecracker penstemon) - part shade, blooms red May to August.

Ipomopsis aggregata (Scarlet gilia) - part shade, blooms red August to October.

Solidago multiradiata (Northern goldenrod) - part shade, blooms yellow July to September

Iris missouriensis (Rocky mountain iris) - sun (6 or more hours of sun a day), blooms purple May and June.

From our Native Plant Image Gallery:

Penstemon strictus

Penstemon eatonii

Ipomopsis aggregata

Solidago multiradiata

Iris missouriensis