July at The Reigate Garden Centre Plant Department
Plant of the Month
The name Agapanthus is derived from two Greek words agape meaning love & anthos meaning flower.
Agapanthus are available in both white & pink however they provide one of the best sources of blues flowers in the garden.
They will remain in flower for weeks and are striking plants with an architectural shape.
After flowering they will develop large seed heads which can be useful in winter flower arrangements.
Agapanthus will grow best in a fertile and well drained, moisture retentive soil, as they will require plenty of water in the summer months.
They will take partial shade but full sun in best for maximum effect. There are both evergreen and deciduous types which are slightly hardier, but both are best protected with a mulch of bark or straw during the winter months.
Plants should be regularly feed with a good high potash feed (such as tomato food) until the flowers start to show. If growing in containers this should be supplemented with a balanced feed during June and July.
When flowering finishes the foliage should be allowed to die down naturally as this will encourage better results next season.
Use underwater plants to prevent acidic water
If there is enough oxygen in the pond water, it will not become acidic. The best thing to do is to ensure that there are enough oxygenators (underwater plants) in the pond. By keeping the water healthy in this way your pond plants will grow better and fish will remain healthier.
Repelant Bearded Iris
Iris germanica flower profusely in June and then die off above ground. If they have been in the same place for about five years, they need to be dug up and the rhizomes need to be divided and planted anew if you want to see profuse flowering next year.
These irises like a dry and sunny spot.
Mix some extra lime into the soil.
The tops of the rhizome should protrude slightly above the soil.
Plant them in a north-south direction.
July is the month for sowing biannuals like forget-me-nots and pansies. It is very important that the seeds remain sufficiently damp.
Shrubs like Kolkwitzia, Weigela and mock orange (Philadelphus coronarius) will have finished flowering at the end of this month and can then be pruned straight away. Prune just above the new shoots or cut the branches down to just above ground level.
Wisteria forms many searching shoots which may extend to spots where you don’t want them to be. Cut them back to around fifteen centimetres.
On grapes cut away excessive foliage which can impede the formation of fruit and cut back shoots which have overshot.
Summer raspberries will usually have finished by the end of July. All the stems which have borne fruit can then be cut back as far as possible. Tie good new shoots (no more than fifteen per linear metre), cut back all other shoots.
Hedges can still be trimmed. The more you trim, the denser a hedge becomes. Of course this works best with a fast-growing hedge.
Some plants can easily develop wildshoots. New shoots can then emerge from the roots anywhere nearby. Well-known examples are Staghorn Sumac, Kerria, raspberry, blackberry, sea buckthorn, all sorts of bamboos and Campsis.
Various perennials like lupins, Delphiniums, Salvia × superba and Achillea taygetea will give a second flowering under good conditions if they are cut back after the first flowering. Often this will be in July.
Maintain the pond
The floating and underwater plants will grow vigorously. There may be a need to thin them regularly.
To keep the pond healthy it is essential to maintain open water.
Leave plants that you remove from the pond lying on the side for a while so that any small creatures in them can make their back to the water. The same applies to filament algae that you remove from the pond (which may also be necessary regularly).
If the water lilies develop too many leaves and hardly flower, it is time to divide their rhizomes and plant them anew.
Top up water
In warm weather you need to top up your pond regularly, since the water evaporates quickly and the water level will drop even more rapidly if there are a lot of marginal plants in the pond water. If possible, use mains water for this.
Ensure that the water jet never hits the pond directly and hard if there are fish in the pond.