Expert gardening in June: Midsummer sees the garden at the peak of its glory, with roses looking particularly beautiful. There’s still time for a last big push to sow annuals
Expert gardening tips for June: planning inspiring ideas
- If you haven’t cut back your box bushes or hedges already, Derby Day, on 4 June, is traditionally the last chance to do so. Topiary shapes can be tricky to cut well at first, but with practice – and special topiary shears – you’ll and it gets easier. If you’re not sure about getting a decent shape it’s possible to buy frames; you simply place them over the plant and cut what comes through the frame.
Perennials and bulbs
- Deadheading is a bit of a chore but it’s essential to keep plants such as roses, cosmos, tender geraniums, knautias and sweet peas flowering. If you leave the flowers to set seed, the plant will think the season is over and stop producing more, but if you cut them off it’s likely to keep flowering.
- Spring bulbs such as snowdrops and bluebells, which tend to clump, can be divided now once their leaves start to go yellow. Dig up the bulbs, divide them carefully either into individual bulbs or small batches and plant them again, giving them more space to grow. They will put on a much better display if they have a bit more room.
- Early-flowering perennials, such as hardy geraniums and alchemilla, can be cut back very hard. They will regrow, look a lot better, and may even re-flower.
- If you’re planting perennials, make sure the plant and the ground are both well watered before they go in. Water again afterwards and keep an eye on them for signs of stress. At this time of year, and if the sun is out, it would be difficult to overwater. Plant summer bedding if you haven’t already, and keep sowing annuals in situ if needed.
- This is the time of year to take semi-ripe cuttings. These are created using this year’s growth while the stem is still a bit soft, and the technique is ideal for plants such as lavender, box, passion flower and heather.
- Take a non-flowering shoot and trim off about 10cm, cutting just below a leaf node. Remove the lower leaves and place the cut end in a container with cutting compost. Then wait to see if it will root and take up water before all of its water is lost through the leaves.
- There’s more chance of success if you keep everything moist, so slip a plastic bag over the top of the container and put it in a sunny spot to keep a good sauna-like atmosphere inside.
- Continue planting salad crops in succession.
- Cover fruit trees, gooseberries and currant bushes with nets.
- Sow runner beans and French beans in lines or with a wigwam of bamboo canes. An old trick is to line a trench with newspapers before putting back the last of the soil so the water stays in place. Be especially vigilant about watering during dry spells as beans really like to have their feet damp at all times.
- Don’t forget pumpkins and squashes – sow now and they’ll be ready for Halloween.
- Plant out late seed potatoes; chitting – leaving them in a warm, dark place to sprout – isn’t needed at this time of year.
- Plant out tender plants such as courgettes, squash, tomatoes and sweetcorn, now that risk of frost has passed.
- Sink a long cane into the ground alongside tomatoes and water well; regular watering is key with tomatoes.
- Don’t forget the second earthing up of potatoes to keep the light away from the tubers.
- Watch out for really hot days, which can dry out young plants. If the temperature goes up, try to water twice a day.
- Strawberries should be ready to pick – make sure there’s straw under the plants to keep the fruit off the soil and look out for runners. If you peg them down, they’ll root and will soon be ready to repot and make new plants. Check for grey mould, especially in wet weather and remove any fruit that have it. Don’t compost them or the mould will get into your heap.
- When the flowers of potato plants go over it’s time to start digging up the tubers. There’s no need to dig them up at once, just take them as you need.
- In early June, try making elderflower cordial. It’s easy and has a lovely summery taste.
- Have you ever walked around a National Trust garden and wondered why the lawn looks so good? Well, one of the secrets is to mow pretty much every day. Keeping the lawn so well trimmed stops the weeds and encourages the grass to grow thickly. Daily mowing is probably too much for most of us, but weekly should be possible, and it will help the lawn look healthy and lush.
- As summer goes on, the lawn may become very dry. In this case, raise the height of the cut for a while. This will be less stressful for the grass and it will withstand drought better.
- If the grass is starting to look less fresh even though it’s being well-watered, it may need a summer lawn fertiliser. This feed has a lot of nitrogen, which will encourage top growth, and midsummer is the perfect time to apply it. Follow instructions on the packet and remember to water it in well after the application if it doesn’t rain.
IF YOU ONLY DO ONE THING…
…This is the last chance to grow flowers from seed. And though it’s late in the season, it can be a surprisingly good time to get reliable results.