How To Propagate Agastache. 3 Best Ways

You can choose from three methods if you’re interested in how to propagate agastache. Agastache or hyssop has different varieties that will surely get your garden to look more lively in summer and fall. And best of all, you can propagate this plant either from seeds, cuttings, or division. 

Perhaps this flexibility in propagation has inspired many gardeners to venture into the commercial production of agastache. But regardless if you’re growing for profit or hobby, take comfort in the fact that growing agastache itself is not meticulous. Those who have a greenhouse can start their agastache indoors and guarantee plants’ establishment without drawbacks from fluctuating weather conditions. 

How To Propagate Agastache. 3 Best Ways


How To Propagate Agastache Successfully


Method #1. Seeds

Experienced gardeners recommend starting agastache seeds in the greenhouse. This will guarantee germination and protection from the potentially harsh climate. Plant your seeds indoors around six weeks before your location’s last frost date, which can be around February to March for transplanting in May. 


Starting seeds indoors

You can use a general seed starting mix, but make sure that it is moist. Cover the seeds as you would when starting other plants and maintain soil moisture and temperature at 55°F. Once the seedlings are around 4 inches tall, you can transplant them in May, either in containers or at the garden with 12 inches of space between each plant. 


Starting seeds outdoors

If you are confident about the weather, you can also sow the seeds directly in the fall since they will go dormant in winter. Once the plants have developed four leaves, you can thin them to a foot apart. It’s crucial to protect the plants from extreme conditions, and it’s worth noting that they will bloom later than transplants, so choose a sowing time wisely. 


Method #2. Cuttings

Some agastache plants will propagate from cuttings instead of seeds. As you can assume, starting agastache from either cuttings or divisions will produce plants true to the parent plant. You can also take them yourself from a plant you fancy as long as it is healthy to withstand the cutting process. 


Collecting cuttings

The good thing about agastache is that you can propagate it either from softwood or semi-hardwood cuttings. Collect the cuttings when the plant is about to bloom and abundant with new growth. A useful tip is if a shoot snap, you can harvest cuttings. 

The ideal shoots are those with different types of leaves. Some might be mature, but some might still be growing. You want to take cuttings close to the crown at varying parts of the plant so that the agastache maintains its appearance. 



Once you have the cuttings, please place them in rooting hormone powder and use a seed-starting medium. Maintain moisture and soil temperature between 68 to 75°F to encourage rooting around ten days. More so, heat around 70 to 75°F at the bottom of the container is optimal for root development. 


Method #3. Division

The final propagation method for agastache is by division, which is also useful for maintaining the plant. In general, this allows gardeners to create more plants from mature hyssop that are starting to outgrow its location. Quite similar to propagation from cuttings, the best time to divide agastache is when it’s developing new growth in spring. 



You also want to divide when the temperature is cool to prevent the roots from undergoing stress due to the afternoon’s heat. More so, the divisions will have already settled when the day gets hot if you divide early in the morning. Dig up the entire plant and decide if you want to split the clump in half if it is too big. 


Separating and establishment

Once you have the clump, you can separate it into sections by hand. Gauge the size of each section so that they have enough roots for establishment. You can choose to start these divisions in the greenhouse or immediately at the garden as long as the location is bright and the soil is well-draining

You can encourage the establishment of the divisions by immediately watering them upon planting and ensuring soil moisture until they grow. If you grew agastache divisions indoors in containers, remember that they will dry faster. Nonetheless, be careful not to overwater agastache during propagation and after establishment.



Whether you want to grow more hyssop plants for your garden or business, you can take advantage of the greenhouse and start your plants indoors to guarantee productivity. Learning how to propagate agastache introduces many opportunities to start the plant from seeds, cuttings, or divisions. 

Starting agastache seeds indoors will have your plants blooming faster than directly starting them in the garden. You also have a higher rate of germination because the indoor conditions are supportive of the seeds. But if you want to create clones of your favorite agastache plants, you can also use the greenhouse for propagating cuttings and divisions. 

Propagating agastache from cuttings and divisions are no different from other plants. Take cuttings or divide when the plant develops new growth and ensure moisture until they root and establish themselves. However, note the type of agastache you have since it may have a specific propagation requirement to develop. 


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