Agastache
To be sure, I’ve grown the old-fashioned lovely Agastache (pronounced Aga – sta – cheee) before all over my garden as it self-sows with abandon but I’ve never grown some of the more modern hybrids.
Heads up
Let me give you a heads-up and a warning about these lovely plants because you’re going to be seeing them more and more on garden centre shops in the next few years. Some you can grow and overwinter and many you’ll kill as they are too tender. The problem will be some confusion in the nursery trade about which are which and some retailers may indeed try to sell the tender ones as hardy because of the common name Hyssop and its reputation for hardiness. I’ve already seen this happening so be aware of what you’re getting.
How To Grow
The Agastache that you’re likely familiar with is commonly called Hyssop. It is a lovely plant with blue flowers that thrives in full sun and well-drained soils. So while I apologize to all who have clay soils for describing this plant, you can grow it quite nicely in raised beds because it isn’t a water-hog and will grow quite nicely in dry gardens once it is established.
Anise Hyssop
Agastache foeniculum or Anise-Hyssop has graced almost every garden I’ve ever grown. This licorice tasting plant is easy to grow from seed and is quite hardy in our local gardens. It is indeed a wonderful plant with its blue flower spikes and if happy, it will self-sow. In this way, you’ll never lack for this plant even if the short-lived mother plant dies off after a few years. The leaves make a soothing tea and are welcome additions to my kitchen herb garden. Drying the plant is quite simple; all I do is take a few branches and hang them upside-down in the kitchen for a week. The leaves curl and brown and once fully dried, they go into a glass jar (I use old sealer-jars) for storage and use in teas during the winter.
Giant Hyssop
A. rugosa is a much taller form and is sometimes called ‘Giant Hyssop’. This plant too is hardy and fun to grow. It will easily top 4-feet tall in the garden and the blooms in early summer are rose to white coloured depending on the plant. While it is a little tender, it will take -10C with little apparent damage. If you can find the seed, it is easily sown and started with no heat mat or other fancy equipment as long as you keep the soil temperatures about 60F. Sow them indoors in May and transplant outdoors in July for blooms the following year. I doubt you’ll find this plant in garden shops but you will find it in seed catalogues or the Internet.
Species Hyssop
Agastache urticifolia is the other hardy form (again to -10C) that you might find in seed catalogues. This one tops out around 6-feet tall and will grow in exactly the same conditions as the previous two. The flowers on this delightful plant are rose to violet shades.
Annual Hyssop
Where
we get into difficulty with tender plants is when we add A. mexicana
to the breeding mix. This plant is quite tender as it is a tropical species but the flower colours are wonderfully blended and varied ranging from bright reds through to pale pink-whites. This gives the plant breeders a red gene and a blue gene to play with and as you can guess, the resulting rainbow of plants is fantastic. These heavy blooming southerly plants are fantastic and the trials I saw last year were magnificently in bloom in a hot spot in small containers. I confess the plant collector in me lusted after them.
The Brighter the Bloom the More Tender
But the brighter the colour of the bloom, the more tender the plant. When you see Agastache on the plant benches this spring, make sure you know what you’re buying.
Do not think you’re buying a perennial when in fact you’re really getting an expensive annual.
And yes, the annual forms will be priced pretty close to perennials if the wholesale numbers I saw are any indication of the retail pricing that we’re all going to see. Having passed along this warning, let me also say that if I can find them on the benches this spring, I’m going to pick up a few, grow them in the garden all summer and try to overwinter them in the fall.
Propagation
In the meantime, I’ve got some seeds started of a golden-leaved annual variety (start at 70F soil temperatures and they germinated in 5-7 days) and while it is tender, it will at least let me ease the pangs of plant-lust for this family of lovely Hyssops.
Other species and varieties start equally easily from seed.
Cuttings can also be taken as can early spring divisions.
If you want to ask about growing Agastache, click here