A slice of lemon and lime
Returning to the yellow and white borders, Tanacetum pathenium ‘Aureum’, better known as golden feverfew, is looking nice just now. I realise that some will regard it as a rather weedy plant but I think it has its merits. For a start, the bright yellow leaves are very cheerful and it is one of the few yellow-leaved plants that is easy to grow and thrives in full sun (more of that later). It straddles being a herbaceous perennial and a shrub. In the first year it is quite soft but the base becomes woody by the first winter and it should be cut down to a woody stump in spring. After a year or two it gets a bit raggedy and is best replaced. Luckily, it seeds freely and the pale seedlings are easy to spot and leave, move or thin.
It is not fussy about soil or site and, in dry shade, the plants will be short and tough. In part shade, like my plants, they will be thinner and not so covered in bloom. It is a lovely cut flower and, of course, has pharmaceutical value, most notably in relation to migraine.
Of similar colouring is Cornus alba ‘Aurea’. With lovely lemon and lime leaves it is a gorgeous thing but can be tricky to place. This is because, in common with many yellow-leaved forms of plants, it needs some sun to develop the yellow colour but is prone to scorch if there is too much sun, especially if the soil is dry. In sunny, dry sites the equally lovely and more vigorous ‘Spaethii’ is a better choice. ‘Aurea’ is a rather delicate creature, which I think confuses people since Cornus alba is generally considered as tough as old boots. My plant is sited in part shade, under my mimosa, and the shade will increase as it grows. This will not do much to develop the red winter stems but that is not a huge problem for me. Like its relatives, it should be cut back hard in March unless, as I intend to do, it is pruned in November and the shoots used as hardwood cuttings to spread it around the garden.
Helianthus ‘Soleil d’Or’ is a lovely perennial sunflower. I have been planting a few of these, which I may later regret if they decide to make a run for it across the garden as they are wont to do. But this one should be a clumper and not a runner and reaches about 1.5m high, though mine, which was only planted in April, is just 1.2m. The flowers are fully double, last so long they are in danger of getting boring and the stems are pretty sturdy.
Lastly is Bupleurum rotundifolium ‘Garibaldi’, a cultivated form of hare’s ear. It is an annual and, although in Apiaceae (the carrot family) it is a satisfactory cure for euphorbia deficiency. Strangely I only planted my first euphorbias in the garden this month – a curious omission. I have no idea why the strain is called ‘Garibaldi’ but this is a hardy annual with rather glaucous young leaves and lovely lime green bracts around the yellow flowers. It reaches about 80cm high and is a rather rangy thing but that makes it useful to grow through other, more solid plants. It will grow where it is sown but I did the usual thing and sowed it in cell trays, a pinch of three or four seeds per cell and transplanted them in May. I hope it will seed around because it slowly gets bigger and better in the border as summer progresses and is useful for cutting. If it spreads around it would be welcome among most other plants (remind me I said that if, in a few years, I start cursing it).
The Biking Gardener 
That Bupleureum looks interesting; one to try. I love the smell of the foliage of feverfew and constantly grasp it when I walk past.
Yes, I like the scent of feverfew too – but then I like the smell of dahlias and French marigolds!