This is a draft of some notes aimed at new allotment holders who have children. Any comments welcomed - email@example.com.
For some of the older allotment-holders children only spell trouble, but if you start children off early enough, everyone can enjoy the experience. We took on an allotment when our children were 2 and 6. In the first few months I hardly visited the allotment alone and half our visits were inspired by the 6 year old. We treated it as a little farm - no flowers, nothing just for show - because it worked for us, but for different children you may need to be less purist about the edible ethic.
It helps to be within short walking distance of the plot. Children may offer to carry tools, but by the end of the trip you'll be carrying everything. An on-site shed or lock-up box would save your arms. A neighbouring plot-holder may be willing to share. Pick a large plot. If you have a young child, try to have a vacant plot next to yours.
Joint planning is preferable, though you may end up having to choose varieties according to their name rather than other qualities. Some seed companies offer selections for children (e.g. Unwins' "Seeds 4 Kids" range) which may help. Having a separate area for each child helps give them a greater sense of success and independence, but if that's the only area they feel part of, they won't have much to do. Whatever scheme you decide upon, having clear paths through your site is useful. And make it very clear to the children that they can't go on other plots.
No special equipment is needed, though the children might appreciate gloves, and it might be a good idea to have one of each tool for each child to stop them squabbling. The tools I use are always the most popular. Car boot sales are a good place to buy cheap tools from.
Safety is an issue, but little more so than for adults. Be careful with sticks and make sure everyone is up-to-date with tetanus jabs. The ends of stakes can be made safe with a rasp, and canes are eye-friendly when topped with an old tennis ball. Collect and dispose of sharp glass and metal debris as it surfaces. Keep on-site some lavender essential oil for cuts, band aids and antihistamine tablets for insect bites. Any chemicals, including fertiliser but especially herbicides and pesticides must be secure from thirsty and hungry raiders. Ensure ponds and water barrels are covered. Water on neighbouring plots is equally in need of protection from young swimmers. Take care of all the obvious dangers from the start so your allotment can remain a place of fun and relaxation.
Accept losses! You won't have time for intensive farming so parts of the allotment will become over-run. Be realistic when you find there's no time to cultivate the whole plot. Cover some of the unused patch with carpet to transform a weed haven into a mud-free play haven - after two years without light even the toughest weeds should be worm-food. Avoid rubber-backed carpets which break down into the soil. Some of your spare ground can also become 'lucky dip' land where a mix of left-over seeds will provide discoveries and delight. Do less weeding in this area and allow some of the crop plants to go to seed. Radishes for example make a wonderful display of (edible) flowers before setting (edible) seed pods which survive well enough for the next season. Some spare corners can be left almost completely untended as mini wildlife reserves. A small pile of logs and leaves may attract many different visitors, including your kids.
Let them get dirty - it's all part of the fun. Even if they're not doing anything useful, as long as they're not doing damage and not taking too much of your time, visits can be considered a success, so praise their hard work even if it's not very productive. Our 2 year old once spent ages filling a little hole with water and finding stones to drop in. We let him get on with it.
You may find that they get all the more enjoyable tasks - you'll have to do the boring things like preparing the ground. Though they'll want to plant seeds, it can be a fiddley job for them, especially if the seeds are small and light - mixing light seeds with sand before sowing them helps to thin them out. You need to balance when they like doing with what they're good at, because it's important that the children succeed. You might like to do some secret weeding so that they think the crops were all their own work. Try to always have some fast growing crops - radish for example - and some things that can be eaten straight away. Things that grow fast and are big (sunflowers, gourds) are popular. Planting seedlings rather than seeds reduces the waiting time. A herb garden works for some children. You could even plot out a world map and grow appropriate plants in each country.
Make the visits short, and be prepared to keep switching tasks. Have picnic breaks if you want to stay more than an hour, or have a break from gardening. There are many non-growing activities you can try. Younger children might like building a mud track for toy cars. Older ones might like to make a pond (frogs eat slugs) or a nature area. An allotment offers the chance for big construction projects. You can get material from skips. We built a compost bin and even tried building an aqueduct out of old guttering from one end of the long allotment to the other. Fencing and netting offer other opportunities. You could even make a plough! But remember that something too ostentatious might attract the attention of vandals.
And as everyone knows, allotment work provides opportunities for chatting while you work. Make the most of it while you can.
The main benefit is that you're with the children while doing something useful, but with luck some crops may survive. Children are more likely to eat vegetables if they've grown them. They may even help with the cooking. They might also enjoy giving their produce away to friends and neighbours.
There are many educational by-products too -
The child's school might like to get involved.
Sooner or later it will happen - the allotment won't be considered "cool", or the mud will play havoc with their hair. Action Man doesn't have an allotment outfit, and none of the Spice Girls dig for victory. There's little point in putting any pressure on at that point. With any luck they'll regain interest in a decade or two - I did!
The World Wide Web has some resources on the subject. Most are small sections in general gardening resources, or resources for Teachers.