Considerations for Fall Planting
by Monica Finn, Horticulture Chair
I am a plant nerd, biologist, and longtime CNPS member. I’ve planned and implemented many restoration and revegetation projects across Northern California with some great results. Here are some general tips to know, especially for new native plant gardeners. Before you pick out plants, you have several things to consider.
Observe Your Site
What are your specific site conditions? Think about your sun exposure, aspect (which compass direction your site faces), and slope. What is your elevation (as this affects average annual temperature range), and what type and extent of precipitation do you get?
Know Your Soil
What types of soil do you have? The proportions of rock, sand, silt, and clay influence the drainage. Most plants can establish in a variety of soils, but some plants that have specific needs or limitations, especially in clay soils. Keep in mind that it’s far easier to plant plants that are adapted to your soil than to try to change your soil.
Let Nature Be Your Guide To Selecting Plants
The plants that naturally grow in your area will be adapted to your site conditions and will likely do best for you and wildlife. Read up on the plants you’re interested in to see what will work best for your conditions. Also note what grows together so you are creating habitat, not just random plantings.
To get the most habitat value, choose plants that vary in flower color and flowering time, aiming for three or more blooming plants in each blooming period. You’ll find more detailed information about selecting plants and site conditions on the Calscape and CNPS websites.
Plant at the Right Time
The best time to plant native plants is in the fall, but if daytime temperatures are still warm when you pick up plants, keep them in the shade and regularly water them until the weather cools. You do not need to wait for the rains; the cooler temperatures of late October and November are perfect.
When ready for planting, identify where your plants will go by placing them over the planting area, keeping in mind site condition needs and mature plant size. Group plants with similar water needs together.
Prepare the planting holes by digging a hole twice as wide as the pot. Rough up the sides and bottom of the hole to make it easier for roots and water to extend outside the hole. Fill each hole with water and let it soak in.
I like to amend the soil for each hole with two handfuls of compost and woody mulch, which will slowly add nutrients and keep the soil open. Note that this is not the same as adding fertilizer. Plant each plant so that they are just above the natural soil grade (1/2 inch); then mulch and water. Mulch with 3 inches of material making sure mulch is not touching the trunk or stem of plants.
Keep New Planted Plants Hydrated
Once plants are in the ground, saturate once a week until natural precipitation happen regularly. Saturate the soil in a two-foot zone around the plant. Check plants regularly and check soil. If the soil is dry at two inches, water the plant.
After your plants have been in the ground a few months, most can be watered every two weeks in the absence of rain, then reduced to every three to four weeks over the summer. Extended heat spells likely require additional water before the heat wave.
These are general watering guidelines; know your specific plant needs. Some natives, such as blue oak, Matilija poppy and flannel bush, are very sensitive to summer water. Wetland and riparian plants need watering regularly throughout the summer. Coastal species need some shade, and likely extra water during hot periods. More detailed information on planting, mulching and watering is available on the Calscape and CNPS websites.
