It is difficult to find information on plants that repel bees and wasps and even harder to find any proof that they work. The reason for this is because bees are pollinators of plants and wasps eat many insects that would otherwise damage the plants. Many plants try to actually attract bees and wasps. There are however some theories out there about certain plants that are claimed to have bee- and wasp-repelling abilities.
Lemon grass, also known as Cymbopogon, comes in 55 different species that are put to many uses. It is in many make-up products, hair products and perfumes. Some people use it to make their homes smell fresh while two species are used in cooking. Lemon grass also has natural insect-repellent properties to it and it is used as an ingredient in Citronella candles and oil. Lemon grass is quite easy to grow as long as it is planted after the last frost. It should be planted in soil that drains well and that has been mixed with compost. Most people grow lemon grass from starter plants; make sure the seedlings are planted 3 feet apart from each other. Because it prefers humid conditions the lemon grass should be watered and misted frequently.
Wormwood comes in a few varieties including the herb tarragon. Wormwood however is listed as a weed in many states, and because of its hallucinogenic properties it is banned in quite a few of them as well. Wormwood is known as Artemisia and can be used to keep animals and insects away. It is often planted as a border to repel animals and bugs from eating and damaging the garden. According to Rick Steinau from asktheexterminator.com, Artemisia is the only plant the he has heard of that works at repelling wasps. Wormwood is quite a hardy plant because of its ability to enter a dormant phase if it gets too hot, sprouting again when the return of cooler temperatures. It can also grow in poor soil and can stand full sun or partial shade. Some varieties can be a little invasive and need pruning regularly due to their likely hood of sprawling. If proven to be effective at repelling bees and wasps this plant could please many who are terrorised by these creatures in their own backyards.
Eucalyptus oil, produced from certain eucalyptus tree species, can be a natural insect repellent. The oil is generally distilled from the leaves through a steaming process and can be used for a disinfectant or a bug deterrent, among other things. It is also very flammable. Eucalyptus oil is often added to insect-repelling products that also contain citronella. The two combined should be powerful enough to keep some wasps at bay.