The Garden House Tasks for June
Posted:12 June 2025
June marks the height of the gardening year here at the Garden House. Our roses are abundant and looking beautiful, but of course they need deadheading – all 100 of them! (except of course the ones that produce hips).
Please bear in mind these tasks are not a comprehensive look at all garden aspects, but relate directly to our monthly work in the Garden House garden, inspiring and teaching the volunteers, students and Friday group gardeners who get stuck in and support the development of this unique Brighton garden.
Now is the time to be quite ruthless with plants that are not looking good and are too close together, so don’t be afraid to thin out. Ideally hardy annuals should be spaced 30cm apart to allow them space to breathe – think caldendulas, eschscholtzia (California poppy), cornflowers etc.
Ammi majus and Papaver somniferum (opium poppies) will need staking. Cut the ammi down to the next set of leaves to stop them for becoming top heavy, and bring into the house (if you dip the stems in boiling water for 15 seconds it will stop them from flopping).
Next week we will begin to sow out biennials (wallflowers, honesty, sweet rocket and white forget-me-nots looked stunning in pots last year).
Larger pots are planted with a mix of tender perennials and annuals and this year we are aiming for an exotic look. We have planted Cannas, Ricinus, Begonia luxurians, Bidens, and Plectranthus. Also brightly coloured petunias, and Coleus (or as they now called: Solenostemon).
Dahlias grown in pots: we’re cutting down to three sets of leaves to encourage them to bush out and produce more flowers.
Regular feeding: we are aiming to feed our containers weekly. ‘Feeding Friday’ seems to help us remember when to do it!
In our new greenhouse we are growing salad crops, tomatoes, peppers and chillies – sowing little and often, using boxes and bowls with drainage.
Don’t forget to pinch out your indeterminate (cordon) tomatoes, and allow your determinate (bush) types to do their own thing.
Cut flowers: to keep us supplied until November, we have grown Cleome, Zinnias and Cosmos to replace the earlier flowering hardy annuals as they go over. Annual climbers, Cobaea scandens, Rhodochiton, and Thunbergia will be ready to replace the sweet peas when they have finished.
Prune summer shrubs such as Ribes, Philadelphus, Weigela after flowering. They flower on old wood and so need plenty of time to make new growth for next year’s flowers.
Cut back old leaves of Pulmonarias now and also Oriental poppies such as ‘Patty’s Plum’ down to the ground (if you feed and water them you may be lucky and get a second flush).
Herbs:cut back chives and mint and freeze or use for cooking – a second picking will soon appear.
Take softwood cuttings from herbs and tender perennials and pipings from Dianthus varieties – these should all root easily.
As ever, there is a lot of weeding to do. Try to identify the weeds in your garden and make sure you alway use a trug when weeding so you don’t transfer things such as ground elder and bindweed on the bottom of your boots.
Now is a good time to summer prune Wisteria. Cut back the long whippy shoots to 5 -7 buds from the main stem to encourage next years growth.
Don’t forget to water regularly and install water butts before a hose pipe ban starts!
Finally, enjoy your June garden and don’t forget to smell the roses!