Not every plant will have survived this summer's hot weather, of that there is no doubt. Plants that were already stressed for another reason, shallow-rooted plants and those with a high water requirement are the most likely to have succumbed to the intense combination of heat, low rainfall and sun-scorch.
You may notice single branches dying off or it may be the whole plant. If it's a single branch, cut back to healthy tissue before any infection can set in and you can usually save the plant. Unfortunately, if the roots have been badly affected then there may not be much you can do and the plant will gradually die off.
Soil cracking open
If your soil has cracked open, as clay soils are prone to do in the summer, fill the cracks with garden compost, well-rotted manure or any other organic matter than the worms can incorporate into the surrounding soil. Not only does this give the plant roots immediate protection from being exposed to the air, but it also improves the soil and reduces the chance of further cracking. Mulching soils like these every year is an extremely useful way of reducing this drying out and the worms do the work for you.
Any plants that are alive, but look dull and lifeless, can be given a boost with a feed of Seaweed Extract plus Iron spayed over the leaves as a foliar feed rather than applied to the base. This works more quickly and acts as a tonic to give the plant an immediate pick-me-up.
Revitalise your flowers
If you go round now and dead-head flowering plants, you are likely to get a second flush of blooms now we all have some rain. Roses will benefit from a liquid feed as you do this and it may save them losing the battle with black spot. Lavender is ready for harvesting to use in cooking or as anti-moth bags in amongst your woollies and you may notice a new flush of flowers already forming. Remember to leave some flowers so the birds can eat the seeds over the winter.
If you are considering replacing any lost plants, don't do it just yet. We might have rain at the moment, but the soil is still dry just below the surface and the plant will get a much better start if you wait a month. The soil will be warm right through until October-November, depending on the weather where you live, and the roots will begin to grow immediately. This will give the plant a better chance of surviving the winter and a head start next spring.
Don't feed as you plant in autumn, because the plant won't have time to use it and the winter rain will wash it away. Wait until spring and apply the fertiliser around the plant, fork it lightly into the surface and water well to wash it down to the root zone.
Try not to regret the loss of a plant: think of it as a chance to grow something new.