The Groundcover and Herbaceous Layers of a Permaculture Food Forest

What makes a food forest garden different from an orchard? One of the distinctions lies in what’s growing on the ground…

In conventional orchards, the ground is either mown, grazed, or even stripped bare and exposed to the ravages of burning sun, and erosion of wind and rain. 

In a food forest garden, we mimic the shelter of the forest floor by planting species that are also edible, medicinal, or otherwise useful in some way. 

Replicating natural conditions, we create a resilient environment where an edible ecosystem can thrive. 

The first layer we talked about was the root layer, of which you can find more information in our article “The Root Layer of a Food Forest.”

In this article, we will explore some of my favorite herbaceous plants and how to best implement them in creating diverse, productive, and effective ground layers in the forest garden.

An Overview of the Ground Layers of a Food Forest

The plants that comprise the ground layer of your food forest garden can be divided into two parts:

1. The groundcover layer. This layer is made up of low growing plants that create a living mulch – protecting the soil and inhibiting weed growth.
2. The herbaceous layer – This layer consists of taller plants that are herbaceous (non-woody species that die back to the ground every year).

The groundcover and herbaceous layers perform a number of important functions in the forest garden:

• They protect the soil from the damage of sun, wind, and rain.
• They suppress weed growth.
• They create conducive conditions for soil organisms to thrive.
• They provide habitats and sustenance for animal life – especially insect species. (See our article on the food forest web here.) 
• They sequester atmospheric carbon – the building block of topsoil.
• They enrich the soil with nitrogen, potassium, and other important nutrients.
• They produce useful crops themselves!

Starting From the Bottom – Groundcover Plants

Low-growing groundcover plants are the key to a low maintenance forest garden. This is because these guys perform the same tasks the gardener would normally assume: preventing weed growth and keeping the soil in a conducive condition for growth. 

To do this successfully, we must choose the right plants that will cover the ground as densely as possible, for as much of the season as possible.

The Best Forest Garden Ground Layer Species

1. Wild Strawberries

Wild Strawberries are a real favorite of mine. Not only do they do a fantastic job at spreading themselves around via runners underneath taller plants, but they provide exquisitely aromatic berries over a long season too! 

2. Wild Garlic

Ramsons and Ramps (a.k.a. Wild Garlic) are some of the most versatile perennial vegetables around.

Great in salads, sandwiches, stir-fries, soups, pestos, and don’t forget to try pickling their flower buds for the gourmet touch!

Ramsons and ramps provide great groundcover but only over a short season…. they’re above ground from late winter until June, so it’s good to back them up with another plant that will succeed them. I’ve found oca and rhubarb work well for this – just harvest them more keenly if they cast shade too early on.

3. Sweet Violets

Sweet Violet (Viola odorata) is the violet from which commercial perfumes are derived.

Wafts of its heady aroma can make one quite giddy on a warm spring day as you potter about the garden! These flowers are sometimes crystallized and eaten as a delicacy, and its leaves can be included in salads.

Sweet violets make one of the best season-round ground covers, even remaining evergreen in milder regions. 

Other Fast-Spreading Groundcovers

Whilst in smaller forest gardens, you may wish for the entire ground layer to be edible, in larger gardens it might be more practical to cover certain areas with fast-spreading, robust species that won’t let any weed in sight!

For this purpose, my top picks would be Dwarf Comfrey, Sweet Woodruff, and Creeping Raspberry.

Taller growing herbaceous species such as Apple Mint and Horsemint will also do a great job at this, as will Russian Comfrey varieties. 

Other groundcover plants I’d recommend would include Siberian Purslane, Rock Saxifrage (Saxifraga), White Clover, Bugle, Pulmonaria and if you’re looking for a self-seeding annual to overwinter – Lamb’s lettuce makes an outstanding salad leaf for the early spring. 

The Herbaceous Layer

The herbaceous layer tends to comprise more of plants that are useful herbs and vegetables in their own right.

Some of these such as oregano, ice plants, and mints can do a great job at suppressing weeds as well, but we can also grow more delicate species like onions and fennel through the existing groundcover of smaller plants.

The Best Forest Garden Herbaceous Layer Species

1. Allium

Perennial members of the onion and garlic family are great fun to include in the food forest ground layer.

Providing fresh leaves and edible flowers for most of the year, these can replace regular onion and garlic in most recipes. Aerial parts can also be pickled or frozen for winter use – so you might even be able to give up buying bulbs from the stores altogether! 

Chinese Chives, Welsh Onion, and Babington’s Leek are some of my very top picks and can be used in salads and cooking every day.

2. Sweet Cicely

Sweet Cicely is a superbly versatile herb that is quite tolerant of shade.

It has a strong anise flavor that might not be for everyone – but if you like licorice allsorts, you’ll definitely love the young seeds of this plant which, to my tongue, taste almost identical! Its leaves, flowers, and roots also make good eating, and once it’s established it’s here to stay!

3. Daylillies

Many of the plants belonging to the herbaceous layer can be very decorative too.

Daylilies (Hemerocallis sp.) are not often grown as a vegetable in the Western world, yet in China fields of them are cultivated for their edible flowers. And a succulent, sweet, juicy flower too!

Its young leaves are also edible in small quantities when they arrive in early spring.

In fact, many perennial vegetables make mock of the so-called “hungry gap” – filling the spring months with an abundance of fresh leaves and flowers.

 Many of these like Good King Henry, Siberian Purslane, Sea Beet, and Caucasian Spinach make wonderful spinach substitutes – and perennial species are usually richer in nutrients than their annual cousins too.

Other herbaceous crops I’m particularly keen on include:

Fertilizing the Forest Floor

We can also utilize the space under the tree and shrub layers to plant species that add nutrients to the soil.

Nitrogen Fixers

Plants such as lupins, vetches and clovers are members of the pea and bean family and as such form a special symbiotic bond with nitrogen-fixing bacteria on the nodules of their roots. This nitrogen is effectively filtered from the air and condensed into solid form for the plant to use. 

When the plant dies back down into the soil as part of its annual cycle, this nitrogen becomes available to other members of the garden. 

Nitrogen is one of the very most important nutrients for soil fertility, so having plenty of nitrogen fixers in the mix is a big step towards the overall prosperity of the garden.

Mineral Accumulators 

Another way we can enrich the soil is to incorporate plants with deep roots that will mine the subsoil for minerals, bringing them up to a level where other plants can access them. 

Russian Comfrey and Lucerne can plug their roots 3 meters (almost 10ft) down into the ground, accumulating nutrients that are out of reach even for some tree species! 

Other tap-rooted herbs like Valerian, Pulmonaria, Rhubarb, Hogweed, Chicory, Borage, and Sorrel also make great deep divers.

When we cut back the leaves of these plants and leave them on the ground, we’re supplying a nutrient-rich mulch to the surrounding soil.

When we plant these “fertilizer plants” near hungry crops such as apple trees and raspberries, we can increase overall yields and diversity at the same time.

Designing the Ground Layers of a Food Forest

Step 1. Decide What You Want From Your Food Forest

As always, the key to starting your design is to ask yourself: “What do I really want from my forest garden?”

In the ground layer, this is especially important. 

I’ve seen many people get into trouble a few years down the line with a ground layer that was ill-conceived from the beginning – without proper attention paid to which crops to prioritize, and where to plant them.

Forest gardening is meant to be efficient and fun – just be sure to be discerning in the beginning and you’ll save yourself a lot of work later on!

Step 2. Write a List of Crops You Want to Harvest

Write a list of crops that you would like to harvest from your ground layers. This should include root crops since they tend to be herbaceous too.

List your crops under categories, namely:

• Salad ingredients – leaves, flowers, and seeds
• Perennial vegetables – leaves, flowers, roots, and shoots
• Herbal teas and medicines
• Culinary herbs

Think carefully about the quantities you’ll need. 

My favorite part of the ground layer is probably the amazing diversity of salad ingredients – yet for these, a few plants go a long way.

If you’re planning on replacing conventional cooked greens with perennial alternatives, you’ll need plenty of plants like Good King Henry or Wild Cabbage to provide an adequate quantity.

As mentioned in our article on roots, you can never really have enough root crops to keep you well-fed over the winter months. 

And also, if you drink lots of herbal teas or like using culinary herbs in the kitchen, then I’d recommend planting plenty of these to ensure you have enough for drying and saving for those seasons when they’re less plentiful.  

Now, let’s think about where to plant things…

Step 3. Where to Plant Your Plants

To maximize harvesting efficiency, it’s a very good idea to think in terms of zones!

You don’t want to have to traipse across your entire garden every time you need to cut some chives to go on your pizza! So, locating plants according to how frequently you’d harvest them is essential. 

Zone 1 – Everyday Crops

Which crops will you be collecting every day?

Plant those ones closest to your house or entrance to the forest garden. Culinary herbs and teas like oregano, mint, and thyme would definitely tick this box.

Zone 2 – A Few Times a Week

Plants that you’d go to every other day or a few times a week would be your zone 2. These might include salad crops and greens for cooking.

Zone 3 – Once in a Blue Moon

Plants that you only need to harvest once in a blue moon can be planted furthest away at the rear edges of your garden.

These might include root crops or plants that only produce at particular times of the year – like globe artichokes and rhubarb. 

Step 4. Harmony Between All Species

Finally, how do we ensure a healthy harmony between all species?

This might be the trickiest bit of all.

Herbaceous plants like to move. Some will do this aggressively through underground rhizomes or overground runners. Others will form clumps that will gradually expand. 

Understanding each plant’s growth habit and being able to see several years down the line is the key to the long term success of your forest garden ground layers!

If we plant an aggressive, spreading herb like peppermint a few meters away from a smaller, more delicate species like strawberries, we might have a real pickle on our hands keeping them apart after a few years.

In the worst-case scenario, we might even need to start again.

To keep each species in their allotted part of the garden, it’s essential to form barriers to prevent them all jumbling up into an epic “who can smother who the fastest” kind of fight.

Barriers, in this sense, could mean a mown or frequently trodden path, or a “living barrier.” Domineering, clump-forming plants like Russian Comfrey and Sweet Cicely won’t let much cross underneath their shady foliage. 

Whilst it might take a bit of research, careful planning really does go a long way when it comes to the food forest garden ground layer. Done well, it can be the most productive layer of all.

For more information on designing your forest garden ground layer in a temperate climate, I’d highly recommend Martin Crawford’s books based on his twenty years of experience in the UK: Creating a Forest Garden and How to Grow Perennial Vegetables.

Last update on 2021-01-29 / Affiliate links / Images from Amazon Product Advertising API