September should be the start of the crescendo of the summer season with our gardens bulging with colour and texture. While some gardens fade at this time of year its easy to tweak your planting schemes and Include some late flowering perennials and a few ornamental grasses which will provide you with that splash of colour we all need before we head into autumn and winter.

Persicarias, also known as knotweeds, have never been one of my favourite plants, until recently, when I saw how well they can be used in a naturalistic setting. The prairie garden seems to be the perfect place for this bold and uncomplicated herbaceous perennial.

Reasonable concern over the potential rambunctious nature of persicarias is justifiable, but a movement to banish all persicarias from our gardens is unnecessary. They are not all thuggish, some are delicate and also suited to the more formal garden too.

Persicaria Firetail is pretty easy to like: a seemingly endless bloom of vivid crimson spikes sit atop bushy plants from late summer and well into Autumn. The flower colour is particularly vibrant on crisp autumn days. A dash of red accents appears in midsummer, and the medium green, arrowlike leaves lighten a bit as summer wanes. However give this plant elbow room, it has a habit of spreading itself out and can often out compete its neighbours if they are planted too close. While this plant is a steady spreader, it is not considered to be invasive in any way.

Persciaria Firre tail is great for ground-cover, for bees, cutting as well as the border too. Its got a  robust approach to life and will generally flourish with a minimum of fuss. It prefers a moister soil so don’t grow it where it gets too dry in mid summer and it will cope with a little shade too. Poorer conditions will restrict their vigour and splitting and re-planting their clumps regularly in autumn will help to keep the plant well behaved in smaller gardens.

Firetail mountain fleece could be a perfect addition to a pond or stream environment and mass plantings can provide excellent ground cover.  However,  I think the best approach is to use them in the larger schemes where you have the depth of border to plant bold swathes a drifts of plants, letting them jostle with other big beasts of prairies, such as Eupatorium maculatum and the aster Doellingeria umbellata, as well as anemones, Vernonia arkansana, Silphium perfoliatum and larger grasses such as Miscanthus sinensis, Molinia caerulea subsp. arundinacea ‘Transparent’ and Panicum virgatum ‘Northwind’, which all have suitable vigour. Persicaria Firetail – very much the Ugly Duckling of the Garden...

Jobs to do this month include:
Ornamental Garden:
• Continue to deadhead.
• Trim Lavenders to woody growth to keep them compact.
• Begin to clear leaves as necessary.
• Keep borders clear of weeds.
• Take cuttings of tender perennials.
• Continue to deadhead bedding plants. Plan for next year’s garden displays.
• Collect seed from perennials / hardy annuals.
• Start planting spring bulbs
• Lift and divide herbaceous perennials.
• Start planting trees and shrubs towards the end of the month and move evergreen shrubs etc while the soil is still warm.
• Collect and get rid of any infected roses leaves.

Vegetable Garden:
• Once the tassels on sweet corn has turned brown check whether the cobs are ready to harvest. When ripe the kernels contain a milky liquid.
• Leave marrows, squashes, pumpkins etc to ripen on the plant. Place fruit on a wooden board to prevent soiling.
• Plant onions / shallots suitable for over wintering (on heavy wet soils spring planting may be preferable).
• Continue harvesting fruit.
• Harvest main crop potatoes.
• Sow winter greens such as land cress, mustard spinach, corn salad and hardy lettuce cultivars.