Why not plant a "Bee restaurant" with one flowering plant for every month of the year!
If you don't have a border available for something like this, why not get 12 biggish plant pots?
Here are some ideas. The plants suitable for pots are marked with a P before the name, (P) means that you can put certain varieties in a pot but some will do better than others. Any perennials will do better in bigger pots as their roots will take up more space than an annual:
January
P Winter honeysuckle – Need to be fed and watered to survive in a pot. This is a climber that can reach up to 2.5 meters in height so provide it with a climbing frame. Will flower till spring. As a bonus, it produces berries in the autumn.
P Wild deadnettle - The dead in the name refers to its lack of sting. Will flower from the end of January all the way till November.
(P) Mahonia – This evergreen shrub also produces berries
February
P Helleborus – This little beauty often is evergreen and loves a shady, not too windy spot in your garden.
P Crocus – Someone described this as a perfect plant for the “keen but clueless” as it is a VERY easy little bulb to grow.
P Snowdrops – Beautiful little perennial with small white flower.
March
P Ajuga genevensis – Flowers till mid-May. This plant is actually best to plant in pots as it spreads fast.
P Pulmonaria – Can sometimes start flowering as early as February and will keep going to April.
P Primula – Very hardy little beauty.
April
P Chives - Will flower in April/May. Herbaceous perennial plant.
P Cornflower – Will flower late April all the way to late summer.
P Lotus cornicalatus – Flowers till mid September
May
Achillea – Flowers till August
Cow parsley – Will flower till July
Calendula – Will flower till mid-summer.
June
P Borage - Will flower till September. In mild weather, it will continue to flower most of the year. Self-seeding annual.
(P) Lavender - Will flower from late spring.
P Snapdragons – Will flower till September
July
P Hyssop - Will flower sometimes as early as June all the way through to early autumn.
(P) Buddleja – Amazing shrub with beautiful flowers and a scent to die for. Requires a very big pot.
P Blue sea holly – Will flower till September
August
P Anemone – Will flower till late October
P Cosmos - If winter is very harsh, wrap the pot in something to protect the roots from the worst frost.
(P) Hollyhock – The dwarf veraities will survive in a pot. The larger ones will struggle if the pot is not big enough. Also, remember that the big varieties will grow up to 6ft tall.
September
P Ivy – Ivy is one of my all-time favorite plants. It comes in all shades of green and is a fantastic plant for wildlife, both for nectar and nesting depending on size. It does take a few year before the Ivy produces flowers.
P Salvia – As with all herbs having them in your garden will provide both you and pollinators with food 😀
P Ice plant – Will do best in full sun and does not like to stay damp for long periods.
October
(P) Abelia – This is another evergreen plant that will produce both flowers and berries. As most shrubs, it will do best if you give it some space so a very small post is not recommended.
P Rudbeckia – Prefers to have some room so don’t overcrowed and this plant will do well in a pot. Make sure it is fast draining.
Crocus speciosus – This will keep flowering sometime as early as September all the way to November.
November
P Wallflower – Will flower throughout the year and is ever so easy to care for.
P Sarcococca hookeriana – Will flower all the way to March and then produce berries. Highly fragrant flowers.
(P) Viburnum tintus – You will need to plant two of these to get it to produce berries but if you do remember that the berries are bad for humans. Birds however love them! Will need a big pot.
December
P Winter aconite – Will do well in a pot.
P Common Gorse – Will provide nectar all through the year. As most shrubs it will need a bigger pot.
(P) Winter flowering cherry – Since this is a tree it will need a substantial pot to be able to survive.