I struggled with what to write in this section as there are so many pests, every single plant seems to have at least one of them and when I started reading about gardening it was overwhelming. In reality though pests are not an insurmountable problem, but they are a problem.
I don't believe in duplicating excellent resources that already exist, so I highly recommend the following existing sources of information on pests:
I'm also in the process of writing guides to individual types of fruit and veg and I will include a few words about their unique pests, where I have something to add. In this section I'm going to write about the broad approaches to pest management and how they work together.
When I first started gardening I made the mistake of reading the section of my chosen guide book on pests. I was terrified, in fact I almost gave up before I started. Once I did start I'd been convinced that everything needed to be netted all the time. I discovered that this caused as many problems as it solved.
I now take a much more relaxed approach, I take preventative measures with the worst affected crops and at the worst times of year, but generally I just relax. I look for the varieties and types of plant that have the least issues and I try to keep the plants healthy and myself chilled.
There are so many books on pests and so many great resources (like the RHS website) that I won't try to provide a detailed guide here. I just want to give you a high level view of my approach, which is relaxed, prudent and effective in my environment.
I also should mention that the allotment is a very different environment than our garden. It seems that allotments are truly a pest heaven, so if you have the option of planting in both, try growing the worst affected plants in the garden, and keep a close eye on them.
Finally be prepared for disappointment, whatever you do you will loose some crops to pests. Mitigate this by embracing diversity.
Pests are inevitable, but you can reduce the risk of them wiping out your crop by sowing multiple varieties and planting them in several locations. We typically try for three locations for an important crop and we rarely if ever get hit badly by the same pest in more than one.
Another important element is multiple sowings, for example if you sowed three batches of carrots, one in March, one in April and one in May you would get very different levels of damage from carrot fly, the same is true of many pests.
You can also reduce pest issues by planting lots of different plants in a single location, no attractive target is presented and one crop can act as a [physical and aromatic] barrier to shield another.
Finally grow a lot of different varieties, a few might get hit, but most will make it through to harvest, we grow 250 varieties a year and a lot more successions.
healthy plants are undeniably more resistant to pests, but how do you get healthy plants. To be honest that's a book in itself. However here are a few headlines: