episode 106 | show notes & advice
In today’s episode, Sarah is joined by Head Gardener at Perch Hill, Josie Lewis. As we transition from winter into spring, and we begin to plan how we want our gardens to look and feel for the year ahead, Sarah and Josie discuss the importance of companion planting, and why the concept is so essential to creating a truly beautiful and productive garden.
in this episode, discover
- The most perfect pairs for a truly healthy harvest
- How companion planting can aid organic gardening
- Top tips for deterring weeds and pests
Salvias and roses (1:46)
Salvias and roses are a very beneficial planting duo. Sarah suggests choosing a healthy and strong rose and then underplanting it with small-leaved salvias. Varieties such as gregii and jamensis work particularly well.
Sarah’s favourite salvias for companion planting:
- Salvia x jamensis 'Nachtvlinder'
- Salvia x jamensis 'Royal Bumble'
- Salvia microphylla 'Cerro Potosi'
The sulphur in their scent profile means that when they warm up, they release sulphur, a natural fungicide, which keeps roses super strong and healthy, and mildew and blackspot free.
Josie explains that it’s best to grow roses in a sunny spot because if you’ve got a fungal spore nearby or a source of infection, the spores rely on moisture to germinate. Therefore, it’s more likely that the shade will speed up the infection, which can be lethal for roses. Underplanting with salvias gives you the best chance possible as an organic gardener, allowing you to forgo pesticides and chemicals.
Josie explains that housekeeping is also essential. If you spot the signs of blackspot, clear anyway any dead leaves which might work as a natural host for harmful spores.
The protective properties of tagetes (4:28)
If your garden is prone to problems such as whitefly and aphids, tagetes (part of the marigold family), help to keep infestations at bay.
Josie explains that tagetes are also one of her favourite companion plants. Expelling a chemical called ‘limonene’, which works as a very strong repellent against flying insects, tagetes will help protect crops, fruits, and vegetables. This method is particularly effective in glasshouses, and Josie adds that you can even buy tabs of the limonene in isolation, which is naturally extracted from the tagetes and a good deterrent.
Tagetes minuta – a popular plant that is now being used in very chic restaurants for herbal teas with a distinct apple flavour, and widely used in perfumery too.
Josie says that this is an excellent plant for killing perennial weeds and insects too. The tagetes exude root secretion which has a herbicidal effect and works well on weeds such as ivy. Although the results won’t be immediate, and the process will have to be repeated year after year, it will gradually begin to work as a great alternative to traditional chemical weed killers.
Sarah explains that fennel works in a similar way, clearing the path around it to make room for its babies. This is often the reason that you might see carpets of fennel, with nothing else around it.
Sarah warns that although tagetes minuta isn’t the most pretty of plants, it’s a stalwart friend with benefits that are truly far-reaching.
The many benefits of Greek basil (10:23)
Popular in Greek cuisine, Greek basil has a distinctive lemony scent which is a good deterrent for mosquitos, due to its citronella smell.
Sarah explains that it’s also used widely in vegetable plots in Greece, where it’s used to underplant aubergines and peppers. The scent naturally draws in pollinators such as bees, butterflies, and hoverflies with its tiny flowers.
At Perch Hill, the tomatoes are underplanted with a mix of Tagetes patula 'Linnaeus Burning Embers', basil, and Tagetes tenuifoila 'Red Gem’. Don’t let them choke the base of the plant, but these varieties will make for the healthiest of tomatoes. Don’t reach for the chemicals, Sarah explains that this is the secret!
Mildew mitigation and other homemade repellents (13:51)
Josie suggests making your own chive tea to keep mildew under control. Chop up chives (that you would usually use in cooking) and soak them in boiling water. Strain once cool. Although this won’t stop it once mildew sets in, it’s an effective mitigation tactic.
Josie also explains that sodium bicarbonate mixed with a tiny amount of liquid soap is also very good for keeping mildew away. Some people might also choose to add horticultural oil to improve the quality of the solution.
If you’re growing ranunculus and have experienced the wrath of mildew, Sarah and Josie say that either sodium or potassium bicarbonate will well and truly do the trick. Sodium bicarbonate is widely available from supermarkets, and potassium bicarbonate is available online and is particularly popular with homebrewers.
Josie and Sarah also use a homemade garlic spray at Perch Hill, which is a great approach to keeping aphids away.
- Take a whole garlic bulb and blitz it in a processor
- Blitz with 250ml of water and then blitz again
- Add an additional 750ml of water and allow to infuse overnight
- Decant the solution into a spray bottle for ease of use
The aphids hate the pungent smell, and although this won’t get rid of them, it works well as a preventative measure.
Creating healthy environments (18:23)
To keep plants happy and healthy, Sarah explains that creating a productive microbial environment is key. With a close eye on ladybirds, hoverflies, lacewings, and many more, drawing these creatures in is really important for building biodiversity.
Sarah explains that hoverflies play a fundamental role in pollinating crops and edibles.
Sarah and Josie’s top plants for hoverflies:
- Alyssum 'Oriental Nights'
- Herbaceous plants with pungent smells
Sarah and Josie’s top plants for parasitic wasps:
- Herbs in general
Ground beetles, hedgehogs, toads, and frogs, all love to feast on slugs and snails which can be harmful to your garden. Fallen leaves will provide an excellent hiding place for ground beetles, be careful of leaf blowers getting in the way of biodiversity
Garden plants that make good companions (23:28)
- Sarah mentions that mint is great for general health in the garden. A great repellent for ants too, introducing a carpet of mint can really reduce infestations. Josie explains that Mint ‘Pennyroyal’ is most effective when it comes to keeping ants away.
- Borage and tomatoes – another popular duo.
- Agastache – long-lasting and highly aromatic.
- Mustards – packed with nitrates to enrich the soil.
- Phacelia Seeds – great as green manure, one of Josie’s favourites.
- Ammi visnaga – lovely seedheads, and flowers for three times as long as Ammi majus. Loved by birds and pollinators too.
Homemade plant teas (24:25)
Josie often makes a ‘fertiliser tea’ from the leaves of the non-invasive Comfrey ‘Bocking 14’, which won’t take over the garden.
- Collect the dead leaves from the comfrey and fill a bucket with water.
- Next, add your leaves, this creates a rich and worthwhile fertiliser. Although, be careful… the odour packs a powerful punch.
- Use as desired.
- Take a wine in the box container and remove the inside. Cut off the corner and hang it from a washing line.
- Next, pack the pouch full of comfrey leaves or nettle leaves, fill it up with water, and seal the top with a tight clip.
- Leave the mixture for around 10 days to infuse.
- Use 10ml of the solution to every litre of water. Comfrey is rich in potash, and nettle is rich in nitrogen, which makes for a broad-spectrum organic fertiliser.