You may have already considered pond safety for toddlers, the need to put potentially lethal garden tools out of reach, and the ways to act around animals you will meet outdoors.
However, there is another hazard that can affect everybody. Curious children may also put flowers or leaves into their mouths that are poisonous, while uninformed gardeners may brush against something which sets off an allergic reaction.
Many plants give off their own warning signs. Some have an unpleasant taste which reduces the likelihood of a dangerous quantity being eaten, while others just do not look edible.
Of course there are the usual suspects to watch out for including monkshood (also known as aconitum), which is extremely toxic. They're often planted under trees or springflowering shrubs at the back of a border, bearing tall spikes of helmeted flowers in blues and purples in the summer.
All parts of the plant are poisonous and a skin irritant, causing burning of the lips and mouth, intense vomiting, diarrhoea and spasms.
Many of us have laurel in our gardens - it belongs to the family that includes apple, cherry, plum and almond. But be warned that when you chop your laurel hedge the sap gives off an unbelievably soporific effect and you may fall asleep.
Some people may suffer an allergic reaction from the sap of some plants, such as rue (Ruta), a low-growing plant with yellow flowers. Its herbal uses may become insignificant if you get sap on your skin, which in sunlight can cause a blistering reaction that can last for weeks.
Anyone who has been to the famous Poison Garden at Alnwick Castle and Gardens in Northumberland will have recognised some pretty common garden stalwarts there.
Hemlock, aquilegia, autumn crocus (colchicum autumnale), laburnum and hellebores are all common plants, and all have different levels of toxicity.
The amount you would have to ingest to do real damage varies from plant to plant.
Other potentially harmful plants include the Glory Lily, Foxglove, and the Dumb cane. Also on the ones-towatch list are Morning Glory, Fremontodendron, Woody Nightshade and the Giant hogweed.
If you think your child has eaten part of a poisonous plant or suffered an allergic reaction to it, don''t panic but do seek medical attention quickly. Go to the accident and emergency department of your local hospital, taking a plant sample with you, the RHS advises.
The main message from the RHS is that you should be aware of the plants which are toxic - and teach your kids that if it isn''t a recognised food, don''t eat it.
Peril: Bloodred aquilegia and (inset) morning glory are two plants to look out for