Last Week of May: Mulching
If there’s one thing you should do in your garden at this time, it’s mulching! This week, we’ll tell you why and how, and we’ll also discuss vertical gardening and growing sweet potatoes.
But first let’s ask...
What Should I Plant This Week?
Mulching Mania!
Mulch has two main purposes: smothering weeds and protecting soil (and soil microbes) from the UV radiation and evaporation caused by sunlight. You will be so glad you have done this come August! You don’t want to smother your plants, so wait until they are germinated and established before mulching. For many veggies, now is that time!
Though we often think of the dyed chips that landscapers spread by the ton this time of year, mulch is any material that covers the soil’s surface. Mulch can be natural materials, synthetic coverings, or living mulches (plants).
If you don’t mulch any bare soil, nature will do it for you—with weeds!
What Kind of Mulch Should I Use?
For an annual veggie garden, use natural materials you have on hand:
Leaves—chopped up with a lawnmower
Straw—not hay (see pictures below to learn the difference)
“Saltmarsh straw”—dried beach grass washed up at the high-tide line (check with your town first)
Cardboard—to cover large areas
Newspaper—for smaller areas, lay something on top so it doesn’t blow away
Wood chips—good for paths but can reduce plant-available nitrogen in the soil (not ideal for around your plants).
Spread all materials thick enough to block sunlight from reaching the ground. That means at least two inches, and add more if you begin to see the soil.
Living mulches, or groundcover plants and cover crops, are ideal for perennial beds, where they out-compete weeds but don’t smother larger plants. White clover is a great living mulch for perennials (not your annual veggie plot) that covers the ground and fixes nitrogen for the plants around it.
Plastic or fabric mulches have their uses (like for sweet potatoes—see below!), but use a biodegradable variety.
Straw vs. Hay
Straw is a byproduct of hay production and makes a great mulch. It consists of stems, is golden-yellow in color, and will not have weed seeds in it.
Hay is composed of many types of grasses and meadow plants and is usually green in color with a variety of textures. It is fed to animals to provide them with a wide array of nutrients. Hay is harvested when many of those plants have gone to seed, and those seeds can become weeds in your garden if you use it for mulch.
Vegetables Growing Up
Most conventional farms plant in 2D. But we live in a 3D world!
At Resilient Roots, we emphasize planting to mimic nature. By using nature’s rules, we can grow more food and improve soil and climate health. And as we said, nature grows in 3D!
There are many ways to incorporate vertical growing in your garden or in containers on your porch! Here’s a short video of great space-saving examples of vertical veggie gardening.
Plants That Love Growing Vertically:
Cucumbers
Tomatoes (they’re technically vines)
Sweet potatoes and yams
Climbing peas
Green beans and pole beans
Melons and squash (but the heavy fruit/gourds will need support)
Greens don’t climb, but shallow roots mean you can plant into vertical structures with “pockets” of soil—like this reclaimed pallet planter or this shoe organizer turned into a hanging garden:
What Kinds of Structures Should I Use?
If you already have a wall or fence in your garden, start there.
Here’s a great overview of different kinds of structures that would be suitable. You could make many of these yourself with common materials (branches, wood, metal stakes, etc.)
Keep in mind how heavy plants will get and build accordingly.
Location, Location, Location...
Vertical structures will cast a shadow to the north. Put vertical plants at the north end of your garden to avoid shading other plants. Or, intentionally plant shade-loving plants (like greens) behind the structure.
Veggie Spotlight: Sweet Potatoes
Easy to grow, delicious to eat, who doesn’t like sweet potatoes? They prefer 70-degree soil for planting—which typically occurs in early June here in in coastal Massachusetts. That day is almost here!
Fun fact: sweet potatoes aren’t in the same plant family as “regular” potatoes. Potatoes are nightshades, like tomatoes and peppers. Sweet potatoes are a vine more closely related to the morning glory.
Planting and Soil Prep
Sweet potatoes can grow in the ground or in containers. They prefer well-drained soil and like it warm. For in-ground planting, trap heat by covering each row with black synthetic mulch a week or so in advance of planting so the sun can warm the soil underneath. We suggest using a biodegradable plastic (corn-based). Here is one example of biodegradable black plastic.
For container planting, choose a dark-colored container with thermal mass to hold heat.
To prepare the beds, create rows of mounded soil 6-8 inches tall. Run two lines of irrigation under the plastic and cover everything with the plastic mulch, making sure to bury the edges in the soil so the wind can’t catch it.
The most common way to plant is to purchase bare-root seedlings (called slips) by the bunch in the store or online. You can grow your own slips if you start in the winter. Keep them fresh for a few days by wrapping a damp paper towel around the bunched roots, or separate roots slightly and plant the whole bunch in a small pot if you need to wait more than four days to plant.
For planting, make a slit in the plastic every foot or so, and plant slips so the root and first half-inch of the stems are covered with soil. A dowel is useful for making holes. See this video showing how to plant slips.
Care
Sweet potatoes are drought tolerant and have few pests, so their care isn’t complicated. Your biggest threat is leaf-munching mammals. Rabbits and woodchucks love sweet potato leaves, so protect them! No leaves, no photosynthesis and wimpy tubers. Sweet potatoes need consistent moisture after planting until established, so plan to water once a week for the first four weeks. After that, if you water once every week or two, they’ll appreciate it.
Harvest
Sweet potatoes need 100+ days from planting to be full-grown. If you plant in early June, you will be harvesting in October. Leave them in as long as you possibly can because they will bulk up in those last few weeks, but dig them up before or soon after the first hard frost because the frost will travel down the stems and damage the tubers. To make them actually taste sweet and store properly, they should be “cured” first in a very warm place for a week or more. We will provide more information about curing in the fall.
Resources:
Check out this guide for growing sweet potatoes from planting through harvesting.
In this video from down under, you can see the entire process of growing sweet potatoes in a container unfold.
To Recap Today’s Essential Concepts:
Mulching means fewer weeds, happier soil, and higher productivity.
Mulch with whatever you have on hand: but not hay!
Vertical gardening mimics nature’s diverse ways of growing and saves space.
Coming Up:
Harvesting, cooking, and storing what you grow. Wait, you can eat beet greens? What does a ripe snap pea look like? WHAT CAN I MAKE WITH 8 POUNDS OF ZUCCHINI?!? Ah, life's essential questions...
Moving forward, as more veggies in your garden are ready to pick, we'll discuss how to eat or store your bounty. Gardening and eating are all part of the same process!
Garden Extras:
Check out Stone Pier Press, a small eco-publishing company based in San Francisco. They have awesome, easy to follow resources on planting a garden for your health and the climate by using techniques we love (sheet mulching, perennial gardening, focusing on soil health, etc.)
Another organization helping people start gardens for health and sustainability is the Rodale Institute in Pennsylvania. They’re a farm, top-notch research center, and strong political lobby for a regenerative, organic food system.
Check out their Build a Victory Garden resources.
And “Rebels in the Dirt” is a Patagonia article about the Rodale Organic Farmer Training Program. Farmers are truly essential workers, and it's essential we train good ones!