Creating A Perennial Garden Bed


Perennial Vegetables (available through the Koanga Shop)

Perennial vegetables are getting a lot of coverage these days. I’ve had a perennial vegetable trial in my garden for a few years, because I’ve been skeptical about many of the claims being made and wanted to see for myself which perennials I considered edible, which ones were easy enough to grow that they could really be regarded as trouble free perennials requiring little attention for most of the year, and which of those so called perennials we still wanted to grow as annuals, because they performed far better when grown that way. I’ve come up with a list of those I consider to be best grown as perennials, and another list of those I consider best grown as annuals.

Reliable Heavy Croppers at the Best Possible Time

The very best thing about perennial vegetables, is that they are reliable, heavy croppers, just when everything else in the garden is at it’s lowest ebb!!!! When we have asparagus, and Globe artichokes, and seakale, and tree collards, green onions and Siberian purslane  to choose from every single day through Spring, we feel like Kings and Queens.

Super Productive for Very Little Work Once Established

The second best thing about these perennial vegetable is how easy they are to grow once you have them established

Perennial Beds in the Vege Garden

These are the perennials that we think taste great, and produce heavy crops, in a permanent perennial bed that is very well prepared, and then composted and mulched once a year only. None of these things would do well in a forest garden situation, they require full light, balanced nutrients and high levels of nutrients, and little competition from other plants, with perhaps the exception of Globe artichokes. Some others might survive but will not be productive.

We grow these perennials  in well prepared double dug beds that are composted and mulched annually, in Autumn, when they have finished cropping, and their energy is going back down the their roots, to nourish the roots ready to drive next seasons production. Apart from the Welsh Bunching onions and Multiplying Spring onions…..the rest of these plants are super deep rooted and do well without even watering over Summer.

They are:

  1. Purple Asparagus
  2. Runner beans
  3. Globe artichoke
  4. Seakale
  5. French Sorrel
  6. Rhubarb
  7. Welsh Bunching onions
  8. Multiplying Spring onions
  9. Tree Collards
  10. Siberian Purslane

See The Koanga Garden Guide for cultural  details  about each off these crops

Establishment of Perennial Beds

If your perennials are going to be a critical part of your diet, which they could easily be, then make the most of the opportunity to get the preparation done well. We only have 1 chance with perennials to get the beds prepared well, and that is obviously before they are planted. We always recommend double digging, or even treble digging (details within The Koanga Garden Guide) and incorporating a lot of organic matter, biochar and balanced fertiliser into the bed.  In a normal Biointensive bed we recommend applying a maximum of 2cm compost when planting, here I recommend adding as much well rotted organic material like compost, animal manure that has been composted, well rotted sawdust, Biochar and EF:Nature’s Garden (400 gms per sq m) onto the top of the bottom trench, before forking that bottom trench open, 4-6cm of organic material  here would be great, and then as you double dig the top layer add as much organic material again as you can get your hands on, including Activated Biochar if at all possible.

Once again add 400 gms per sq m of EF:Nature’sGarden with the organic material into the top trench. This will get your plants humming, and mean that from now on an annual application of compost and mulch should be enough to keep them humming and super productive and healthy.

  1. Please note that if you have a very very low level of calcium availability showing on Reams test you may also need to apply calcium carbonate fertiliser as well, I recommend EF:NanoCal, where the calcium is held by the carbon so it doesn’t disappear down to the centre of the earth with the next rain!

Ongoing Management of Perennial Beds

Even our favourite perennial vegetables need the right minerals in the right relationships, moisture and microbes to grow and produce high quality crops and heavy crops of food for us.

The challenge, as ever, is to design a system that is regenerative as well as easy to manage.

We’ve gone back to the classic Bill Mollison design we built in Kaiwaka 30 or more years ago of having a well insulated chicken house/straw-yard with a greenhouse on the front. The chickens keep the vegetables warm in winter, and they provide the compost to replenish the beds each year. They also provide carbon dioxide for the plants and the plants provide oxygen for the chickens. We are in a cold winter climate here so having a space to extend the season is very important to us.


When we practice Biointensive gardening we grow all the carbon we need in our vege garden to be able to produce as much compost as we need to grow and build soil in our Biointensive vegetable beds. We will not, however, have enough compost to also compost our perennial berry beds and our perennial vegetable beds., unless we specifically design our carbon crop production to ensure we do (see our New Koanga Art of Compost Booklet – This will be released any day now!)

I’m not into making work for myself so I’ve been figuring out a way of producing compost that does not mean extra beds or bringing in industrial mulch which will more than likely contain glyphosate or any number of other poisons I don’t want in my garden.

Composting Using Chickens

The answer for me lies with my chickens. Our chickens have a chicken house that makes compost, lots of compost… a laying hen produces 500gms of chicken manure each week, and half of that at least will be in the straw-yard they are kept on until noon each day. In order to absorb that nitrogen we have a deep litter of carbon all times. Manure that is not held by carbon volatizes back into the atmosphere and we need it in our biological systems together with carbon to create proteins, and growth in our plants and animals. The best things (easiest for us) we have found to provide that carbon are the tree prunings from the forest garden (we also use them to make Biochar and firewood, and generally mulch back down into the first garden floor), and deciduous leaves from the deciduous trees in the wider area. I also throw the corn cobs, and husks, in there as we feed the corn to the chickens through out the year.

The critical factors here are:

  1. Having small enough bits of carbon that the chickens can turn the compost over, and
  2. That there is enough carbon going in to absorb the nitrogen to ensure we don’t get an anaerobic situation that gets smelly and difficult to deal with.
  3. That we feed our chickens high quality nutrient dense food such as soldier fly larvae chicken minerals, high brix corn, meat scraps and forest garden insects and greens so their manure is also high quality producing high quality compost. We get our chicken compost tested and find that it needs added calcium.. lime or bone ashto keep the mineral; balance right.

I find it works best adding a little carbon at a time, keeping the compost sweet smelling and quite decomposed so that there is plenty of microbial and fungal activity for the chickens to eat.

We have 8 chickens and 1 rooster, and this means we produce enough compost each year to put 2cm of compost on the 50m long x .8m wide perennial vegetable bed as well as our 20sq m of berry beds, and their will be plenty left for  other special things such as arguta kiwi fruit, and flower beds.

When we remove the compost always leave plenty to re-innoculate the next brew and speed up the composting process again.



I leave the asparagus bed in Autumn until I have my vegetable garden Biointensive beds all planted and away for the winter….. then I check the asparagus bed for weak plants, and female plants that I would have marked during the productive season. Each year I might remove the two or three least productive plants (out of 30 plants planted at 50cm diagonal spacing) and replace with a crown from the most productive plants. Males are generally more productive than females and in commercial asparagus field they only grow male plants. I have to keep females because Koanga needs the seed, but we carefully manage the bed to ensure we continually improve the line.

Once I have the plants sorted I compost the bed with compost from the chicken straw-yard that is composted forest garden pruning chips, plus Biochar plus EF:Nature’sGarden. Once the bed is composted, I cut the tops off the asparagus, and lay them down onto the compost which stops the birds from scratching it all up.


Runner Beans (P.coccineus)

Management for Runner Beans means ensuring their roots are well mulched over Summer when they need to be cool and moist, well mulched over winter if you are in a heavy frost area to keep them from freezing, and an annual compost and fertilize in Autumn to prepare their roots for strong Spring growth. If you have compost that had EF:Nature’s Garden in it then you won’t need to add any more fertiliser.

Top Tip: Search ‘runner’ in the search bar at the top of the page in our Online shop to see our full range of runner beans.


Globe Artichokes

Once the Spring flush of globe artichokes is over, simply compost the bed and lay down all the chopped off old stems over the compost.. the old stems will act as a mulch.



Seakale roots go straight down to the centre of the earth . Once the tops die back in Autumn simply compost and feed and mulch with whatever you have around, possibly rhubarb leaves and stalks…. at this time there will be lots, or old and long grass cut with a garden shark from somewhere else in the garden or forest garden etc. Anything to cover the compost which will be exposed while the seakale is dormant.


French Sorrell

A must for anybody serious about living from your garden. French Sorrell is not only the easiest vegetable in the world to grow, it is a mineral accumulator, an also one of the best tasting of our bitter herbs. We eat French sorrel leaves most days in egg dishes and salads, year round. The best way to keep it strong is to make sure you regularly cut all of the leaves off at ground level each time it gets huge and strong. Cutting a leaf or two off at a time will not encourage growth.  An annual compost will be enough attention for this amazing plant.



Management of rhubarb consists of an annual application of either compost or well rotted organic manure, regular removal of all leaves that were not eaten at the optimal stage ( mulch them straight back down under the plants) , and every year I dig up one of my 5 plants and break up the crowns and give them away and replant the strongest. Over 5 years that means we will have renewed all plants keeping them young and vigorous. The best time to manure and dig and break up old plants is in early Autumn so that the plants produce well again next Spring.


Welsh Bunching Onions See The Koanga Garden Guide for cultural details

I keep my Welsh Bunching onions going by removing the flower stalks and cutting all leaves  back to ground level every time I need to, until our Shallots and other onions are harvested, usually all by late January early Feb. At that point when we have other onions, I cut the, off at ground level and apply a deep application of compost. If Welsh Bunching onions dry out they get aphids so watering is critical with this perennial crop, they do not have deep tap roots like other perennials.


Multiplying Spring Onions  See The Koanga Garden Guide for cultural details

Multiplying Spring Onions grow actively in the opposite season to Welsh Bunching onions so they also are a valuable addition to the perennial garden. When they die down in Autumn simply compost heavily. Like Welsh Bunching onions they must not dry out over Summer or they also will get aphid attacks ( because of plant stress)


Siberian Purslane  See The Koanga Garden Guide for cultural details

A super easy plant that will just keep self seeding and spreading and providing us with really delicious greens most of the year in shady places, under the asparagus, or the artichokes, or the rhubarb or amongst the Welsh Bunching onions etc, establish it in a few moist places and let it go..give it a sprinkle of compost every now and then.