Fortress Plants – Guardians of the Food Forest

What are Fortress Plants?

From a scientific point of view, there’s no such thing as Fortress Plants.  From a Permaculture point of view, however, they are an integral part of the Forest Succession process.  Being plants that have evolved to repel grass, they perform a vital function in  preparing the ground for the coming forest.

Grass does not grow in the woods.  It’s too shady.  Fortress plants grow in that borderland between Forest and Grassland.  You could call them the frontline of Forest Advancement, as they help the Forest expand into Grassland.

In Permaculture Design, they are used in a way that mimics the natural forest succession, and eventual expansion.  They are frequently planted as a way to protect the garden boundary, to stop the invasion of grass and other weeds, and as guild borders, enclosing the fruit tree and all her understories.

Fortress plants help with lawn reclamation and can even deter animals.  They’re the ones who are the biggest influencers when it comes to the particular combination of companion plants within a plant community.  Think of Fortress Plants as part of the internal infrastructure of your garden design.

How do Fortress Plants Prevent Invasive Plant Species from Taking Over?

This is both simple and complex…like everything in Nature. Fortress plants are either perennial or self-sowing annuals that spread vigorously.  They have large root, bulb or rhizome systems and produce such thick growth, both above ground and below that nothing can get through.  They’re the ultimate bouncer and will keep out even the much-hated bindweed.  The aggressively spreading rhizomes of red-hot poker don’t let anything through. 

Many Fortress Plants are allelopathic, to some degree.  This means they emit mildly toxic secretions that inhibit the seed germination and/or root growth of other plants.  This isn’t as bad as it sounds.  There’s a full range of compounds, from the mildly subtle to the furiously intense.   

Bearberry, for example, (Arctostaphylos uva-ursi) is a small-leafed, cold-hardy perennial shrub or groundcover.  In addition to growing quite thickly, she also has several allelopathic phytochemicals that will keep other things out.  She’s also a good pioneer plant, as she can grow in poor soil conditions.  Bearberry is a solid understory layer that produces lots of bright red berries beloved by bears, migratory birds and humans.  She can really hold the fort.

Another example is Elderberry, Sambucus nigra.  She has very mild allelopathic properties that are barely noticeable…unless you’re a Douglas Fir, which she prevents from growing.  From a permaculture perspective, Elderberry is a marvelously abundant source of biomass, able to put on 4 to 8 feet of growth in the first year alone.  They also respond well to aggressive pruning, so they can be pruned to bush out for a shrubby sub-canopy layer, or allowed to grow tall.  This makes her an excellent mulch plant.  The pruned branches can be composted, used in  hugelkultur beds and erosion barriers. 

Their large and abundant flowers are in bloom for much of the growing season, so they attract pollinators.  Any orchard would benefit from having several Elderberry trees scattered throughout. 

On top of that, she produces an extravagant amount of delicious immune system boosting berries.

But it’s not just woody shrubs or trees that function as Fortress Plants.  Edible daylilies, garlic or the more aggressive Jerusalem artichoke are all delicious and will all pull their weight in the Forest Succession process.

Comfrey, of course, is the Queen of Permaculture Plants. Fortress Plant, extraordinaire, she is many things.  A deep digger, her 10-foot deep roots draw up minerals, making her a major nutrient accumulator.  Her nutrient-rich leaves make magnificent mulch; they are as packed full of Nitrogen, Phosphorus, and Potassium as any manure.  The leaves, being relatively low in fiber, break down quickly, dissolving in a couple days into a rich fertilizing tea.  This will activate compost piles.  A fast grower, she provides a lot of nutrient-rich biomass.  Her deep taproots will stabilize hilly areas.  Her allelopathic roots fend off grasses.  Chopped and dropped, she is a weed suppressant mulch. 

And her medicinal qualities are legion.

Protection Energy – With Culinary and Medicinal Uses

It was once believed that wild-type systems could not support domesticated food plants, that cultivars had to be civilized, helpless, catered to, babied.  Fertilized.  Poisoned.  That they have to be queued up in straight artificial rows, because that makes harvesting them easier.  Even though living like that diminishes them, making them totally dependant on us for protection, and, by extension, making us their slaves.  Because if we grow certain plants to eat, they cannot have any other purpose in life.  They certainly could not be considered to be part of a “community.”  This is not a healthy symbiosis.  It’s a sick one.

It’s yet another expression of this insane dominator culture, that ruins, literally, everything it touches.  So the idea of plant autonomy?  The notion that plants can create protective barriers for themselves and each other?  That they can communicate in ways we can’t understand?

Poppycock!

Because anything that goes against the dominator’s narrative is, obviously, poppycock.

But it’s obviously not poppycock.  Permaculture has proven, time and time again, that cultivars can exist in these situations.  Not only exist, but thrive.

Gardens are most frequently made in places with full sun, water and decent soil.  Which are also the places that grass prefers.   Gardens are also considered a lot of work.  Working against Nature is futile and exhausting.  Working with Nature is easy, in comparison.  The natural inclination of grasses in a full sun, water and good soil area is to spread.  Without a way to deal with the grass, gardens can fail due to grass encroachment.  So it only makes sense to create plant fortresses against this.  To establish plant communities that can reclaim the fake and totally immature monoculture of a lawn and replace it with a wonderfully thriving mature Food Forest.

And on that note, I will leave you with this list of Fortress Plants.  It is certainly not exhaustive.  The intention is simply to provide you with a great springboard for your own research.

clover   

comfrey

creeping phlox

daffodils, tulips & crocus 

dandelion

garlic, chives & other alliums 

gooseberry

Jerusalem artichoke 

lemongrass

lilies

lovage

Maximillian Sunflower 

plantain 

red-hot poker

rhododendron 

sea berry

sorrel

 

Have Fun With It!

And. as always, I love to hear from you!