Wouldn’t it be wonderful to choose the best plants for the job that needs doing?

To select species that grow well whatever project you’ve got planned – veggies, living mulch, green manure, a windbreak… We’d save so much time and money buying replacement seeds and plants.

It is often not hard to find lists of plants for different projects like windbreaks, green manures and cover crops.

But it’s not the best way to grow.

It’s equivalent to getting candidates for a job vacancy before you’ve sat down and sorted out what job they need to do.

Recently a neighbour of mine was telling me how he had tried growing living mulch. He’d brought a bag of Cowpea and Lab Lab (Dolichos Bean) seeds, and spread them under his vines.

“It hadn’t worked,” he said. “It was more trouble than it was worth; plants climbing all over my passion fruit vines.”

I wasn’t surprised.

Cowpeas will climb when they get the chance, and LabLab is a vigorous legume, with a strong preference to being upwardly mobile!

He hadn’t worked out the Selection Criteria for his living mulch species list.

If he had, he would have listed ‘inability to climb’ as one of his Selection Criteria. Any plants with a partiality to climbing are definitely not suitable candidates for passion fruit trellises.

In fact, anywhere there’s a climbing frame.

Writing a job description for your planting projects doesn’t take long. And, you’ll come up with a selection criteria that will make a big difference to the success of your project.

Let’s look at an example – creating  a job description for Green Manure

The job of green manure plants is to protect and improve soil, and also reduce undesirable plants.

Green manure plants need to grow fast to quickly provide a protective cover over the soil and grow masses of plant biomass.

Additionally desirable, but not essential skills: nitrogen-fixing, deep roots to till the soil and pull up nutrients, and flowers producing pollen and nectar to feed beneficial insects.

From this job description, I put together this selection criteria.

  1. Grow quickly
  2. Grow heaps of biomass to increase organic matter levels in the soil
  3. Include plants with nitrogen-fixing bacteria
  4. Grow a dense canopy – undesirable plants (weeds) will then find it difficult to germinate and grow in the low light levels underneath
  5. Seeds are cheap and easy to obtain
  6. Grow less than [a desired height]
  7. Grow deep roots
  8. Non-climbing
  9. Running plants on larger sites – need less seed to cover the site
  10. Set seed about the same time – we don’t want some plants setting seed early and then germinating and growing up amongst our vegetables

Have I forgotten anything?

Would you have thought of the last two criteria?

When I grew my first green manure crop, I didn’t think about the need for the plants to set seed about the same time. Consequently, the millet seeded early and I had it coming up amongst my veggies for years afterward!

select plants like this one
Lacy Phacelia (Phacelia. tanacetifolia) is a popular green manure species. It is native to the arid southwest region of the USA and Mexico


There’s one important selection criteria I have left out

Can you guess what it might be? It’s an essential criteria to include whatever your project.

Any guesses?

Answer – will your candidate species grow well in your growing conditions? Will they be  happy plants?

It’s crucial.

If your growing conditions (soil, shade, drainage, etc.), don’t meet the needs of the candidates you have selected, they won’t grow well and get the job done.

Your green manure crop will be a flop!


So, next time you’re planning a new planting project, hold off from grabbing a generic species list…

Grab a cuppa or a cold beer and put together your job description and selection criteria.

Select plants by choosing candidates that will:

  1. Grow happily in your growing conditions
  2. Diligently perform the duties you have specified in your job description

And behave themselves by not scrambling all over your other plants!

Get to know your growing conditions by creating a GrowMap

Now you’re ready to ask friends, check books, websites, seed and plant stockists. You know exactly what you are looking for!

It won’t take long and you’ll save heaps of time and money on expensive mistakes.

Happy planting!

Image of Phacelia by Evelyn Simak          Lead illustration © BioDivLibrary

“Yours is the only newsletter that I actually read”

That’s what we hear from our subscribers