Weather patterns have been just right recently for diseases such as potato blight and downy mildew.
Many potato aficionados will quake in their gardening shoes to think of the approach of blight. It was the disease responsible for the Irish Potato Famine where crops of this staple diet were wiped out.
Foliage and stems show black patches of collapsing cells and this travels down the stem into the tuber. The first thing to protect the crop would be to cut off affected foliage to stop this process, but then there will be no more weight of crop put on.

News of a possible onslaught comes from a website, Blightwatch.co.uk
Information supplied on an hourly basis by the Met Office monitors weather conditions. Potato and indeed tomato blight can occur when, for at least two consecutive days, the minimum temperature is 10 degrees C or above and on each day at least 11 hours when the relative humidity is greater than 90 per cent.

These conditions are called Smiths Periods.
Now here comes the scaremongering bit. With all this information to hand the website reveals that the disease has been confirmed at postcode PE28.

Anybody in or near this area would do well to use a copper-based product to protect against infection. This is all you can do, protect. There is no cure for this problem.
Then onto downy mildew. It would appear that there is a nationwide problem with busy lizzies.

Symptoms here include a white marking on the upper surface of the leaf while on the underside, with a hand lens, you can see the fungus sending out purple hair-like structures.
Leaves drop and the stems turn black rendering the plant useless. Dead material should be handled very carefully.

Spores, or fungal seeds as you may think of them as, can lie dormant for some time. Try to remove all dead material, bagging it up rather than walking across the garden and potentially spreading the problem.
If left on a compost heap which is not generating high temperatures, the spores will not be killed.

It's better to put plant material into the plant recycling bin. The spores can remain viable for some time so it would be best not to plant busy lizzies next year. Consider begonias, (begonia semperflorens) instead.

The fungus will not spread to other species, only to other busy lizzies or impatiens as we should more correctly call them.
The disease seems to be rife in the crops of commercial growers as well as in our gardens. But if you have bought plants from a nursery that were infected before you bought them, you may feel you have a claim against your supplier.

In growing your own plants, and if weather patterns are to change, try to keep air movement up by ventilating the growing area.
On a slightly more cheerful note, but not much more, winter is coming. That means it is time to sow pansies and wallflowers. Neither crop likes too much heat during the germination process so keep seeds and seedlings as cool as you can in hot weather.

In the case of pansies do make sure you are sowing seeds for winter flowering and not summer bedding varieties. Pansies are probably the best source of winter colour, being resistant through harsh weather and are ever present throughout what could be a dull season. Colour your world next winter, sow pansies soon!