Updated: Jun 30, 2022
How to not kill your native plants
So you’ve decided to oust some of your lawn in order to make way for a Mini Nature Reserve, but you’re a bit nervous. In the past, when you tried to spunk up your garden with new plants, everything perished and now you are fully convinced that you are brown-thumbed. You were so excited to bring home all of those beautiful flowers you found at the nursery that day but by the summer, you get back to where you started. The truth is every good garden (even a native garden) requires planning and acknowledging the realities of your space. Below is a foolproof plan for finally planning a garden that doesn’t die.
The Mini Nature Reserve Project (MNRP) favors a “ground-up” approach to landscape design. In traditional landscape practice, people usually choose the plants they want only taking into account the sun exposure and then change the soil and conditions of their site to allow for those plants to thrive. They might add customized fertilizer to increase the amount of phosphorus or add coffee grounds to make things more acidic. In a ground-up approach, one bases the plant selection on the conditions of the site making no or only minimal changes. An example of this is planting seaside daisies or sea thrift at a beach house.
Step 1: Remove any lawn that exists on the site you want to convert to native landscape.
There are many ways to kill grass without resorting to pesticides. MNRP recommends halting watering during a dry period, removing all grass with a hoe, laying down newspaper, and then covering it with mulch.
Step 2: Lay out paths and any hardscape features such as swales and boulders. Before you do any digging, please call 811 dig alert. People will come out and draw lines where you can't dig.
Step 3: Know your site
Once all the paths are laid out, the swales are dug, and all the unwanted lawn space removed, you now want to become familiar with the conditions of your site. We recommend testing these conditions in several different spots of your garden. Since one spot might differ from another.
Sun exposure: Is it full sun, part shade, full shade? Does it get morning or evening sun? Is it against a south-facing or north-facing wall? Are you planning on putting a tree or a shady structure? The best way to figure this out is to choose a day and check on the site every hour.
Soil Texture: For this, MNRP recommends performing a mason jar soil test and then plugging in the percentages into this calculator.
Drainage: Dig a one foot deep hole and fill it with water. If it drains in less than half an hour, it is fast draining. If it drains in less than an hour, it is medium. If it still has water after an hour, it is slow draining.
pH: pH tests are available at any nursery.
Square footage: it is important to know the size of the space you are working with so you don’t overcrowd plants.
Also take note of any observations you make such as whether or not there is gravel in the soil. Its proximity to the swale.
Do some research! Find out what type of ecosystem your location supported before it was urbanized.
Step 4: Pick your plants
Once you know all the conditions of your site, you can base your native plant selection off of that. For people who live in California (the state MNRP is based in) Calscape is a great tool. All you have to do is click "Advanced Search" and plug in all the conditions of your site as well as your location. It will then give you a list of locally native plants that would grow well in your specific spot.
When you find a plant, calculate the total area of the plant. (A=1/2 plant width squared x 3.14) If your total area of your selected plants matches or exceeds the total area of your site, you have too many plants! It’s always nice to leave some unplanted space for wildflower seeds.
Remember to also take into account the plant’s height. It wouldn’t make much sense to plant a sunflower patch in the foreground and a poppy meadow in the background. All you would see is the sunflowers! Some places like park strips also require that the maximum height for a plant be 3 feet.
When choosing your plants, take into account what it looks like at all times of the year, not just when it’s in bloom. It’s generally a good idea to use evergreen plants as a foundation and then scatter deciduous plants in between. It’s also a good idea to choose plants that flower at different times of the year so that there’s always something in bloom.
Remember that areas near a swale or any water feature will always have more moisture than areas further away. In the Northern Hemisphere, soil along a south facing wall receives more sun than a north facing wall and is therefore, drier.
Step 5: Plant your plants and water them to watch them grow.
The best time to plant native flowers is in the fall right before the rainy season. Dig your holes twice as big as the plant container's width. Fill the holes with water and let them drain multiple times. Make sure the plant is level with the ground, then create a doughnut shaped berm around the plant. Create a moat on the other side of this berm to allow water to soak into the soil without touching the crown of the plant. Give your plants plenty of water during their first few months of life. Wean them off so that by May, you aren't giving any more supplemental water.