There’s no denying homemade compost is weedy and we’re actually chucking many of the offending weed seeds into the compost bin just now as we tidy the beds. But rather than ‘contaminating’ their precious soil with this terrible compost, some people would sooner consign weeds to the green bin or even landfill. This is a ludicrous thing to do.

I admit you can’t kill every seed in a home composter because you need to heat compostable material to 60C for seven days. Although this is done when producing commercial growing media, beneficial organisms as well as seeds and pathogens are also destroyed. Nutrient is then added to this inert compost.

Beneficial organisms keep working in home compost so the nutrients are gradually released and the structure better maintained than in what you buy.

When trying out a new compost, I always test it against my own by growing and assessing one variety in pots containing each type. My compost always wins, as my detailed results show.

You not only produce better, if weedy, compost but can be sure of having a sustainable product that emits little CO2 when being produced.

Here in Scotland, the remaining 5-10% of our peat reserves contain 1.7 billion tons of carbon and it should stay in the ground.

But with so many people taking up gardening during last year’s lockdown, garden centres often ran out of peat-free compost and gardeners were often forced to use peat-based stuff.

Although data isn’t yet fully available, it looks as if this was repeated this spring. So we must all do our bit for the environment and make our own compost.

Do some weeds in the compost really matter, even if they’re likely to ‘outwit’ us? During its brief 6 week long life, groundsel, Senecio vulgaris, could donate between 1200 and 1700 seeds to a bed.

Even if you weed before seeding, it’s reckoned up to one third of potential seed will still germinate.

So it’s no surprise that groundsel and its bedmates, nettles and chickweed are first to emerge from freshly scattered compost and only high temperatures kill them off.

Some seeds are less resilient and can be destroyed at temperatures as low as 40C in as little as three days. But some of these weaker souls will still survive home composting.

A compost thermometer only records heat in the top 30cm of fresh material. Unless you solemnly turn the heap every week, seed at the side and bottom will emerge unscathed.

Regular hoeing greatly reduces the number of weeds and mulching denies light that’s vital for germination. As organic mulch breaks down, it adds weed-free nutrient to the soil.

Mulching largely controls more persistent perennials like couch and ground elder, which use a spider-like web of roots to dominate a piece of ground.

But they often nestle between the roots of shrubs and you fight an endless war, removing what you can round the perimeter of the bush.

Apart from bindweed, horsetail and of course Japanese knotweed, most of these perennial weed roots can also be composted. The roots are highly nutritious but do take two years to rot down.

If you use compost from a plastic bin after one year, you’ll easily identify any white couch or ground elder roots and yellow nettle ones. Simply throw them back for a second year.

We can’t allow these roots to reestablish, but some seedlings are worth rescuing.

I often come across dill and aquilegias and admire the resilience of tomatoes. Seedlings of Ragged Jack, one of my favourite kales, always get planted.

Plant of the week

Berberis thunbergii, Japanese barberry, has fresh green leaves in spring and summer that turn fiery shades of orange and red in autumn. Pale yellow flowers are followed by clusters of glossy, red fruits that have a tart, lemony flavour. Use, sparingly, in rice dishes.

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