Salvia microphylla San Carlos Festival (rear of photo) has been pruned back now

Pruning has been on my mind a lot this week; not least perhaps because I finally got my hair cut - the first time in three months! My garden is looking as scruffy and bedraggled as my hair was, and I was itching to do some pruning. A friend had told me that she prunes some of her Salvia back in May, and her plants are always certainly far more advanced than mine in spring, and flowering merrily whilst mine - normally pruned in mid-August - are just recovering from their drastic lopping. She told me that the types that she prunes now are mainly the cultivars of the compact, small-leaved ones such as Salvia microphylla and Salvia greggii and the many hybrids that have been developed by crossing these two species (known as Salvia x jamensis, including the 'Mesa' range, which are good plants for Sydney). She also cuts back any other Savia that have new growth coming through at the base - which I already do tend to do for Salvia leucantha, 'Meigan's Magic' and 'Phyllis' Fancy' when these finally finish blooming in winter.

Salvia Indigo Spires (rear) will also be pruned soon

Salvia Indigo Spires (rear) will also be pruned soon

So I decided I would cut back my small-leaved ones now, so I hacked into them today and found the job incredibly satisfying. Normally, the shabby old growth that stays on there all through winter till my usual pruning time drives me mad as I keep gazing at it - especially on those Salivia that grow just outside my kitchen window! Interestingly, I found that some of these Salvia (such as 'Mesa Azure') actually had new growth forming at the base, which I hadn't expected to find. I cut these ones back quite hard, just leaving the new growth. The others I chopped back by about a third, as suggested by my friend. She also mentioned 'Indigo Spires' and 'Mystic Spires' as two others that can be done now (which I normally leave till mid-August), and these annoy me with their scruffy old growth through winter too, so they will be lopped back too. Examining them today, I saw they had new growth at the base.

Lantana cultivar in the garden of Margaret Chedra in Sydney

Lantana cultivar in the garden of Margaret Chedra in Sydney

In recent years, I have started to trim back all my Plectranthus in May. Previously, I was worried they might die if cut back before winter, if we had some very cold nights. However, winters in my garden seem to be getting milder, and the Plectranthus haven't been affected by their autumn pruning so this has become my usual practice. It is a relief to remove their dishevelled stems after blooming is over and it certainly neatens the garden. In the case of plants that look very woody, I take cuttings so I can start again in spring; they tend to become unproductive after a few years. In very cold suburbs, I would leave the pruning of Plectranthus until spring. Buddleja can safely be severed back hard now in all gardens. Lantana cultivars (again which I normally leave till August to cut back) can, according to my friend, be pruned hard now. They tend to get very untidy and fling their stems in a wayward manner at this time of year. These Lantana are non-seeding cultivars and are good plants for long-lasting colour in the garden. Evergreen shrubs can be trimmed to shape now.

Erigeron karvinskianus can be cut back hard now

Erigeron karvinskianus can be cut back hard now

Summer- and autumn- flowering herbaceous perennials benefit from being cut back to the ground now to tidy them up - Japanese windflowers, perennial Phlox, Echinacea purpurea, species Geranium such as 'Rozanne', and Solomon's seal are the main ones of these in my garden. I also cut all the sad old stems of my Dahlia to the ground today. Another plant that can be attacked now is the seaside daisy (Erigeron karvinskianus), which has formed large curtains of foliage throughout summer. I cut all mine back almost to the base today and I know they will regrow through winter and bloom in spring. I also give these another prune in mid-summer when they have become unkempt again, and they will give another flush of growth and bloom after that. They are indestructible so don't worry at all about massacring them! I like to think the plants are as relieved to have all this old growth removed as I was when I had my locks shorn this week!

The plants that I would not shear back at this time are anything at all that is at all cold-sensitive. These are usually plants that come from subtropical parts of the world, and Sydney's winter is too brisk for them to cope with if they don't have the protection of all their old growth. Examples of such plants in my garden are coleus, Pentas, Begonia, any Acanthaceae specimen, heliotrope, Iresine, Alternanthera and Hibiscus. Most of these I leave until the end of August or the beginning of September. I will be leaving most of the rest of my Salvia pruning to mid-August as usual!

Canna can be cut to the ground in winter

Canna can be cut to the ground in winter

Other pruning can be done in winter, such as perennial grasses, Camellia sasanqua, roses, Hydrangea (if not already done earlier in the year), hybrid Fuchsia, deciduous fruit trees and citrus trees, where necessary to remove old wood. I also cut Canna, daylilies and Kniphofia leaves to the ground in winter to allow them to produce fresh new growth. Staggering the pruning in the garden is helpful if all the cut-off material is shredded for the compost heap, as it is in my garden. It is also beneficial to spread out the pruning workload, as it too can be an enormous job if carried out in one fell swoop as I have normally done, in my mid- to late-August blitz. The other great advantage of pruning some plants now is that it gives scope for growing some annuals in the resultant gaps. My friend scatters many annual flower seeds, such as poppies, in her spaces. I plan to sow seeds of some quick-growing winter salad crops and herbs in mine.