Plants that survive a Folsom summer

A plant list for Folsom has to clear one bar: survive from May to September with almost no rain, daily highs averaging 94 degrees in July and August, and irrigation restricted to assigned days. Plenty of attractive plants sold locally cannot do that without more water than the schedule allows. The ones below can, and they are organised by the structural job each one does rather than alphabetically, because a planting plan is a set of layers rather than a shopping list.

Canopy: the layer that matters most

Shade on the west and southwest walls of a house does more for summer comfort and cooling load than any other single landscape move. Two speeds of tree are worth planting together: something that gets there in five to seven years, and something that will still be there in eighty.

• Chinese pistache. Fast enough to matter, tough in heat, reliable autumn colour, and a manageable eventual size for a suburban lot.
• London plane. Big, fast, and everywhere in the Sacramento region for good reason. Needs room; not a small back yard tree.
• Crape myrtle. Smaller scale, long summer flowering, comfortable in reflected heat next to paving.
• Valley oak and interior live oak. The natives. Slow, eventually enormous, and worth planting for the decade after next. Both resent summer irrigation once established, so they need their own place in the hydrozone plan.
• Western redbud. Native, small, spectacular in early spring, and content on very little summer water.

Structure: evergreen mass that holds the design together

Without an evergreen backbone a low-water yard reads as a collection of objects in gravel by the second winter. These are the plants that keep it looking like a garden year round.

• Manzanita. The signature foothill native. Mahogany bark, grey-green leaves, and genuinely no summer water once established. Sensitive to overwatering, which is how most of them die.
• Ceanothus. California lilac. Evergreen, blue in spring, fast, and best planted where nobody will be tempted to irrigate it in July.
• Toyon. Native, tolerates sun or part shade, red berries in winter, and shears into an informal hedge if that is what a fence line needs.
• Coffeeberry. Unfussy, handles dry shade under oaks better than almost anything, and reads as a solid green mass.
• Pacific wax myrtle. The screening plant when a fence needs covering fast and the exposure is not brutal.
• Rosemary and germander. Mediterranean, aromatic, mostly ignored by deer, and happy in reflected heat.

Mid-layer: the flowering and seasonal interest

• Lavender. Needs sharp drainage. In heavy soil it goes woody and dies out from the middle, which is a soil problem rather than a plant problem.
• Salvia, both native and Mediterranean species. Long flowering, heat-proof, and the single best group for bringing hummingbirds into a yard.
• Ribes, the native currants and gooseberries. Winter and early spring flower when nothing else is doing anything, and comfortable in part shade.
• Yarrow. Flat flower heads, tolerant of poor soil, and useful as a transition between planted bed and rougher ground.
• Agave and aloe, in the right spot. Architectural and very dry, but they need drainage and they should never sit where someone walks past in shorts.

Ground layer: what replaces the lawn

• Deer grass. A large native bunchgrass with real presence. Cut back hard every few years and it comes again.
• California fescue. Finer, softer, good in part shade under oaks.
• Muhly grasses. Autumn flower haze, heat-proof, and a strong contrast against block walls.
• Native sedges. The closest thing to a walkable green surface that does not need lawn irrigation. Works in shade, not in blazing afternoon sun.
• Creeping germander and prostrate rosemary. Dense evergreen cover for banks and the tops of retaining walls.

Establishment: the part that decides everything

Drought tolerance describes an established plant. Almost every failed low-water planting in this area failed in its first or second summer, because it was treated as low-water from the day it went in the ground.

1. First summer. Deep drip watering on the assigned days, aimed at the original root ball as well as the surrounding soil. Emitters placed at the edge of the can, not a foot away where the roots have not reached.
2. Second summer. Same days, longer intervals between soaks, and watch for wilting in the first serious heat wave rather than watering on a fixed assumption.
3. Third summer onward. Most of the natives on this list can hold on with occasional deep soaks, and some need none in an average year. Keep the drip installed regardless: a rainless September after a dry winter is exactly when an unirrigated planting is lost.

What to leave out

Thirsty lawn in full sun, unless it is being used by children or dogs. Birch and other cool-climate trees that spend August looking scorched. Anything sold as tropical, which in this climate means anything that needs summer water at a rate the schedule does not permit. And bermudagrass, which arrives uninvited, survives everything on this page, and is the reason a lawn conversion sometimes has to be excavated rather than sheet mulched.