Agastache, also known as hyssop or hummingbird mint, is a beautiful and versatile plant that can add a pop of color and attract pollinators to your garden. One of the great things about agastache is that it has the ability to self-sow and spread, which can be both a blessing and a curse depending on your preferences and garden space.
If you want to encourage the spread of agastache, you can simply let the flowers go to seed and allow them to scatter naturally. The seeds will fall to the ground and germinate, giving you new plants in the following season. This can create a lovely, naturalistic look in your garden as the agastache spreads and fills in empty spaces.
However, if you prefer to control the spread of agastache or if you have limited space, it’s a good idea to deadhead the faded flowers before they have a chance to go to seed. Deadheading involves removing the spent flowers by cutting or pinching them off at the base of the stem. This prevents the plant from self-sowing and helps to keep it contained.
In addition to deadheading, you can also prune agastache in early to mid spring to promote more flowering stems and a more compact plant. This is done by either tipping the new growth, which means removing the top few inches of the stems, or by cutting back the entire plant to about half its height. Pruning in this way can help to encourage bushier growth and more abundant blooms.
It’s worth noting that some varieties of agastache are more aggressive spreaders than others. For example, Agastache foeniculum, also known as anise hyssop, tends to self-sow more readily and can spread quite vigorously if left to its own devices. On the other hand, some cultivars, such as Agastache ‘Blue Fortune’, are less prone to spreading and may stay more contained.
In my personal experience, I have found that agastache can be a lovely addition to the garden, but it does require some maintenance to prevent it from spreading too aggressively. I have grown Agastache foeniculum in the past and loved the way it attracted bees and butterflies, but I had to be diligent about deadheading to prevent it from taking over the entire bed. On the other hand, I have also grown Agastache ‘Blue Fortune’ and found it to be much better behaved, requiring less maintenance to keep it in check.
Agastache is a versatile and beautiful plant that can add a lot to your garden. Whether you want it to spread and fill in empty spaces or prefer to keep it contained, proper deadheading and pruning techniques can help you achieve the desired result.
