Morning - can I join?
I am an organic hort teacher/community garden manager/allotment and garden owner - I do alot of food growing.
Salad - is a cool crop and doesn't like it too hot. So grow it early in the season, and in the hot summer, grow it in a shady space. Sow little and often [a pinch each week or two].
I read on here that you either plant garlic on (or thereabouts) the longest day and harvest on the shortest, or vice versa. Ie you can do both. Half right. Sow on the shortest day and harvest on the longest is ideal. But you can sow between Mid Sept and Mid Dec, and if you really have missed the boat, sow before the end of Jan. Garlic grows best over winter, and if there is no frost it doesn't split into cloves [last winter no frosts and last summer, no cloved bulbs which reinforced that theory]. During the winter it puts roots down, and then after the Spring Equinox is starts to bulk up. It doesn't work the other way around, as all you will get are roots, and no bulk.
Soil - is 25% air, 25% water, 45% minerals and 5% hummus [or organic matter]. The minerals are sand, silt and clay and the perfect loam [for growing food in] will be a mix of 40% sand, 40% silt and 20% clay.
To avoid spending loads of money on soil, don't fill your beds up immediately. Try lasagne gardening, where you put a layer of kitchen scraps, then a layer of cardboard, then old compost, newspaper etc etc [google it] and when your plants have root balls the size of your fist, you break through the lasagne and plant it, and backfill it. Over the first year, the components break down giving you a lovely loamy soil and you can do it again next year [adding well rotted compost as a layer itself] and saving you load of money.
My top tips are:
Hedge your bets, sow small amounts of different varieties rather than loads of one so that it extends your range and seasons.
Grow organic seeds, the more local the better, as they will be from stronger stock and as they are saved from plants that are growing in your region, will be more likely to be successful in your region. Most seeds in the UK didn't originate here, they were forced in some well maintained, polluted hothouse and we wonder why things fail over here.
If you can't grow organic, local seeds, join the Heritage Seed Library, or grow Franchi seeds. HSL seeds are grown by themselves or by Seed Guardians and this means they are suited to the UK, and taste much better; and Franchi are also the only family owned seed merchant, are based here in Harrow and many of the seeds they sell originated from parts of Italy that have the same climates as we have.
Grow healthy plants - if a plant is not looking good, get rid of it. It may spread disease, and if it is ridden with bugs that automatically reduced it's resistance. Spraying with all sorts of rubbish to keep it limping on is a false economy. Much easier when your seed is vibrant and fresh and local.
To get better ranges of seeds - swap them! Package up your excess, and participate in local or online seed swaps. For the price of a stamp you can really extend your range thus hedging your bets [see first top tip].