Spring in the Greenhouse

zuchinni and living mulch mustard and marigoldEarly zucchini, African marigold + mustard

It’s mid-spring in the greenhouse and no bare soil remains. Once the heat starts, so too the pressure on the soil, so I keep things healthy with a mixed living mulch. Apart from lupin, which I sow after the chooks have been through, the rest are that wonderful guild of super useful plants – self-seeders.

The greenhouse began like all of my other gardens, full of buttercup, dock, nightshade + grass. Deep mulching and weeding while small eventually got on top of the plants I didn’t want. Tossing seed of the plants I did want in their place filled it back up in the way I wanted. Letting the chosen ones go to seed means I can remove myself from this job ever after. The greenhouse groundcovers are set in play.

Borage for Bees

  • One of our best friends in the organic garden is borage and I’m happy that she survives all but the hottest months in my greenhouse. I need her to bring in the bees and nourish the soil.
  • African Marigold and Shoofly help deter pests above and below ground and feed the bees as well.

  • Nasturtiums are another key player – winding through the lemongrass, under the grape, around all the edges and up the walls as far as I’ll let her, providing a catch crop for aphids and piles of mulch material.
  • Nourishing chickweed and cleavers thrive in spring but die off when it heats up, recycling all their goodness back.


  • Mustard is a biofumigant for the soil as well as flowers for bees and fodder for mulch.
  • Lupin provides bursts of nitrogen as long as I don’t let her flower and a lovely deep tap root.

The simple act of tossing about seed brings so many benefits. These humble plants keep the soil active, beat out weeds, moderate soil temperature and help hold moisture. When they get too bossy I simply break them off and pile them on the soil as mulch. Chop and drop mulching is a quick easy job that beats weeding any day.

greenhouse cukes

By late September when the first cucumbers, tomatoes and zucchini go in, the ground is cloaked in green. As I need to, I create spaces to plant into, chopping back the greenery and using it as mulch. As the crops grow and fill the space I chop back more and more groundcover until come January the jungle is mostly tomatoes, peppers, eggplants, basil and cucumbers instead.

greenhouse tomatoes planted amongst saladings ediblebackyard nz

There’s a line to walk here between healthy airflow and being wild. The season dictates how this plays out – and every year is different. When it’s wet and hot, I chop back the jungle as risk of fungi peaks in this plastic coated room. When its hot and dry, the jungle improves cropping no end.

Topping up your mulch regularly with fresh material is a simple but hearty way to look after your greenhouse soil. How efficient (and we could say resilient) to use the stuff that grew there to do this job. Full circle, homegrown and perhaps best of all, plastic bag free gardening.

This morning while I was watering, I rescued the dwarf beans from a salad/ nasturtium takeover bid. I picked the salads for tea and the rest of the ‘weeds’ became mulch.

pre weeding

Beans being outdone by salads and nasturtiums

Chop and drop enough just to create good light and air.

beans rescued

Beans are rescued!


  1. Kate Mcadam says

    Thanks for the info Kath. Your green house looks awesome. I’m hoping to build something like this. What a paradise you have created

    • Nice to hear from you Kate! I highly recommend a greenhouse 🙂 worth the effort for sure not only for all the food it brings but a warm, cosy escape… girl shed!!

  2. Sue McConnell says

    Thanks for your wonderful website, full of such practical tips!
    Just wondering if you need to stake or use a frame for dwarf french beans?
    Also, do bush type tomatoes need staking to stop them flopping over? I have lost a couple where the delicate stems snapped from folding over.

    • A stake is always useful if they flop over and in general where the weight of the crop pulls the plant over. For dwarf beans, I push a stake in at each end of the row and loop string around the stake and then the outside of the row of beans and again around the stake at the other end, holding the whole crop gently upright.

      • Sue McConnell says

        Thanks Kath, I will get on to this straight away to save any further damage due to these winds we have been having.

  3. I love to see what pops up voluntarily in my garden and with your encouragement I’m now leaving it until I recognise it and need the space. Also leaving some to gob to seed to be sure to see them back next year. Such a great way to garden🙂

  4. Ruth Elizabeth Harrison says

    Hi Kath, I remember from one of your blogs you mentioned that you like to grow tansy. Can you please tell me if this is the yellow or the purple flower please? I have just bought a pot of the yellow flower. I read it is best to grow it in a pot if you don’t want it to spread like crazy. Now I’ve just read about the purple tansy and wondered if this has a similar effect. Thanks

    • Hi ruth. I love them both! Tansy proper, aka bachelor buttons – cute yellow button flowers, the awesome herbal companion that spreads madly on free draining soils ( no problem at all on my clay base) is very different to purple tansy flower aka phacelia which is an annual and one of my must have summer companions. High in nectar like borage, the bees love it and it does wonderful things to soil. I scatter it amongst vegies – its soft foliage winds through. I let it self seed. Its easily removed when its not wanted. Great for compost and mulch too.

      • Ruth Elizabeth Harrison says

        Thanks very much Kath! I’ll put the yellow one in a pot then, as we have sandy soil, and will keep an eye out for some phacelia!!

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