With one edge of mountains and one of sea, the soils of California have developed a unique and occasionally hostile composition that has forced an insanely beautiful and huge diversity of plants to evolve in our region. When it comes to getting your garden ready to be native friendly there are a few big pointers to consider:
Drainage is the SINGLE most important element for the survival and good health of California Native plants. Many of our most beautiful plants are adapted to growing on steep rocky hillsides where water seasonally flows past but rarely sits on the plant's roots. This means that many California native (and other drought tolerant plants) get sick and even die when water sits at their roots especially during hot times of year when water would naturally be the scarcest.
How to know if you need to improve soil drainage
*note if your soil is very sandy - like almost a beach - you DO NOT need to improve drainage).
Most articles recommend doing soil drainage tests with rulers and hole digging. For those of you who are too busy to get out the tools we're just going to give you some basic guidelines because pretty much all of our yards could benefit from drainage improvement (*except if you live on the beach or have obviously sandy soil). For those of you who are meticulous or like a little science experiment click here to get thorough details on conducting a soil drainage test.
You should improve your soil drainage if:
- If you live in the suburbs on a relatively flat/graded lot or garden area, your soil will most likely benefit from improved drainage.
- If water pools remain after it has stopped raining for longer than a few hours
- If you've tried native or drought tolerant plants in your yard before and they've died within a few months or weeks, even with 2-3x week watering
How to Improve Soil Drainage
It can be tricky to apply one-size-fits-all solutions to improving soil as every bit of dirt out there is a little bit different. So use your instincts and if something really doesn't feel right when you're doing it reach out to us or a professional and get feedback.
- When planting, dig your holes 6" wider than the plant pot and 1-4" deeper then line the bottom of your hole with 1-4" deep of sharp gravel or sand
- IF planting a large area, turn the top 12" of soil over with a tiller and mix in a yard or two of sharp gravel, sand or DG to roughly equal 1/4 to 1/3 of the new soil composition. Order gravel by the yard here.
- IF you have a very high clay content (very obvious draining issues, rock hard digging when soil is dry, stains hands when wet, etc) modify this to be half sharp gravel, sand or DG and half compost to ensure you don't accidentally make your soil into concrete. Mix in a good amount of hydrated coconut core to really to really do the job.
- Drainage Makeover: If mixing rocks or sand into your soil makes you uncomfortable, instead add the happy spongey texture of coconut coir to do the job of adding breathing room for plant roots. You'll need a big bucket or empty garbage can to soak the bricks in to expand the coir for mixing into your dirt.
- Compost: Add an inch of compost or worm castings to your soil surface, just lightly scratch it in to the surface, don't mix too much. Ensure the top of your new plants soil lines up with top of your compost layer (not sunken, not popping out too much)
- Mulch: Top your soil or new compost layer with a good inch or two thick of mulch, like wood chip, DG (decomposed granite), gravel, straw or dried leaves. Learn where to get mulch here: Mulch Much?
In general, always add more organic matter to your soil over time. This helps to build humus or topsoil, the spongy nutrient rich layer that sits on top of subsoil, feeds your plants and helps store water. This means leaving leaves or small branches that drop from your trees, adding additional mulch and straw every year or two or even spreading shredded paper.
FUN FACT: worms lovvvve shredded newspaper, and old hay or straw.
It might take a little work to get your gardeners adjusted to not raking up every bit of dropped leaf or some getting used to for you to accept the new look of what a happy garden looks like but do it for your plant's sake!
Most California native plants do not like fertilizer. This is because many of our soils are naturally depleted. In fact, as Southern California plant ecologist Edith Allen once told me, their restoration work for native plants often starts with de-nitroginizing soil - or removing excess soil nutrients common in fertilizer and livestock poop.
BUT that doesn't mean your soil doesn't need improving, particularly if it's like most suburban or urban lots whose soil has been driven over by big machinery, dumped with old cement or paint water and basically dead as a doornail for 30-50 years or more.
*If you have more or less wild land as a component of your garden, do not worry about amending your soil for native plants, except for maybe a few worm castings.
Here's how to pimp out your soil for California Native plants:
WORM CASTINGS: the caviar of soil amendments
Worm castings (or worm poop) are an ideal additive for any plant. They are the main component of most naturally occurring top soil and offer a perfect fertility balance and can even help cure plants of disease (for major or widespread plant lackluster try a compost tea treatment!).
The best part about worm castings? You pretty much can't overdo it. There is no risk of plant burn, they are a totally gentle additive. Like all amendments, top dress lightly or up to 1-2 inches deep in a 1-2 foot radius around your plants root zone.
Compost: feed the flora
What to feed your plants. Take away: no compost is better than cheap low-quality compost. For native plants, look for milder compost blends that won't shock your plants with too much nitrogen or phosphorous.
- Only buy organic microbially active compost (look for mycorrhizae content in the ingredients or description)
- Cow (checkout bu blend) or mushroom composts are ideal
Free Compost Ideas
- Pickup horse manure from a stable - grass seeds can be a concern in some scenarios - but often the rye or wheat seeds can act as a green manure crop in your garden.
- Mushroom compost can be made at home with a little patience and initiative. Take a good pile of green waste, messy mulch or wood chip (contact a local arborist to get a free dump) and then mix in a good chunk of King Stropharia aka Wine Cap Mushroom mycelium (shop here).
- The mushroom mycelium will digest the pile for you and give you delicious edible mushrooms while in the process. Depending on the size of your pile this can take a few months to a few years but if you get eager and want to spread the mulch pile in your garden early no worries! King Stropharia mushrooms form beneficial partnerships with plant roots and are even known to increase the size of vegetables when grown nearby.
More resources: California Native Plant Society