Waste Not Want Not, Compost Style

Monday, 07 September 2015

The nights are getting darker earlier (not that I would know as I’m already asleep way before it gets dark) so it must be getting towards the end of the growing season. So, what do you do with your compost in containers and grow bags once your plants have stopped producing? Read on for my top tips…

We always have around 100 tomato plants in containers, so have heaps of old compost

The most obvious thing is to just dig the remainder into your borders and raised beds. It seems strange that you can add more compost each year and your beds don’t overflow. It’s the same with farmers spreading muck each year, the fields don’t become skyscrapers either! But if your old compost has been healthy, without any pest or disease problems, there are loads of more interesting and helpful ways you can use it in the garden:

• You can add it to your compost bin in layers with other garden and kitchen waste. This will give your compost a wonderful structure for retaining water and can add some nutrients.

• If you have large containers to fill each year you can fill the bottom with old compost. Weeds won’t be able to grow if they are well buried.

Fill the bottom your tubs with old compost and top up with new

• Sieve your old compost to make a fine seed compost. Seeds don’t need any food from the soil to germinate so the low nutrient levels aren’t a problem. The lighter structure makes it easy for seedlings to push through. This means it is also good for covering outside sown seeds in clay soil where a fine tilth is hard to get. Use it to help level a sloping garden or border.

A dumper truck helps cover the seeds with old compost

• Carrots don’t like too many nutrients either or they don’t set good roots. You would end up with lots of small carrots with bushy foliage if you give them too many nutrients. Mix your old compost with some horticultural sand and a bit of fertiliser for happy carrots.You can even reuse the compost to grow a whole new crop of produce. Compost used to grow tomatoes can still be used to grow leafy veg like salad leaves or kale. Just make sure not to try to grow the same crop again as it can lead to pests and diseases building up. It’s crop rotation for your containers. Just add bit of general fertiliser.

Mix your old compost with sand
and some fertiliser for perfect carrots

• Scatter it over your lawns and rake it in (or let the worms do the work for you as we learnt on my recent blog). This helps add nutrients to the soil below your lawn.Pick out any clumps of roots and scatter it around your borders as a mulch.

Those are my ideas for reusing your old compost, can you think of any others?

You might also be interested in my blog There’s a Worm at the Bottom of the Garden.

Big hugs,

Euan