Hyssopus

( HISS - op - us )

At-A-Glance Information

This fragrant, compact Mediterranean perennial commonly called Hyssop or Herb Hyssop needs full sun to light shade and moderate to regular waterings. The flowers will attract bees and butterflies to your garden. They reach about 2 feet tall and 3 feet wide, and are woody-based. Leaves are dark green and glossy. On these plants, the foliage is what carries the scent, not the flowers. Dark blue flower spikes form in summer and fall. Varieties with pink, white and lavender blooms are also sold. Hyssop grows best in USDA hardiness zones 3-9 or Sunset growing zones 1-24. To find your zone, click here: Zone Map. The genus Hyssopus includes 7 species, one of which is widely cultivated (Hyssopus officinalis), and is a member of the plant family Lamiaceae, making these plants close relatives of Agastache.

Caring for Hyssopus

Plant Hyssop in full sun; ideally they should be getting between 6 and 8 hours of sun each day. These plants can tolerate partial shade, but can get leggy if they do not get enough sun, and will also not flower as well. Choose a space in the landscape that can handle some light re-seeding activity. They prefer soil to be rich, well-draining, and have a pH of between 7.0 and 8.0. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Add a layer of organic compost to the planting area to suppress weed growth, increase soil moisture retention, and maintain soil temperatures. Water new plantings regularly as they establish a strong root system. At maturity, they are considered somewhat drought-tolerant, and thrive with light waterings. As a general rule of thumb, water when the top two to three inches of soil feels dry. Do not overwater Hyssop plants, as this can cause root rot issues to take hold.

Fertilize yearly in early springtime with a application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Prune to remove spent flowers, which will encourage more blooms to emerge as well as discourage reseeding, which can lead to flowers escaping from their garden spaces. Hyssop plants can be sheared into a low, fragrant hedge if desired. These plants are grown for between 4 and 5 years in the landscape, after which time they become overly woody. Dividing plants every three to four years is recommended for best plant health, and to ensure that new plants do not need to be purchased on a regular basis. For instructions on how to divide these plants, see the Propagation section below. In areas with cool winters, cut the plant all the way back to the base and cover with a few inches of mulch to protect roots from freezing temperatures. These herbaceous perennial plants typically live for between 5 and 7 years in the landscape before needing to be replaced. They have a tendency to naturalize, however, and volunteer seedlings can be dug up and replanted elsewhere.

Caring for Hyssop in Containers
Hyssop plants are wonderful in the ground, but can also be grown in containers. Choose a container that is at least a few inches wider and deeper than the nursery pot or root ball. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Once established, waterings can be lessened. Herb Hyssop plants grown in containers will need more frequent irrigation than those grown in the ground. As a general rule of thumb, water whenever the top few inches of soil feels dry to the touch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every few years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot.

Harvesting Hyssop Plants
Hyssop plants can be grown as members of herb, potager, or vegetable gardens as well as being great ornamental plants for local pollinators. The leaves have a peppery, bitter, minty taste and can be used in cooking. The leaves are commonly used in the distillation of certain liquors and are what gives the beverage Absinthe its green coloring. They can make a good alternative to sage in most recipes, and are also used in teas and to make essential oils. Grow about two Hyssop plants for use in cooking, or between 10 and 20 plants for tea and making preserves. Leaves can be harvested as needed before the plant goes to flower.

Disclaimer: Information contained on this website is strictly and categorically intended as a reference to be used in conjunction with experts in your area. Foraging and consumption of plant parts should never begin without the guidance and approval of a local plant specialist. The providers of this website accept no liability for the use or misuse of information contained in this website.

Propagation

Hyssopus can be propagated either by division or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Hyssop plant, follow the instructions below:

Propagating Hyssopus by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed heads on plants are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will continue to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
In either late winter or early springtime, get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 1-4 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 72 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Hyssopus by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in very early spring (after the plant has entered dormancy, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root(s). Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick root section attached.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divisions and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout in the next growing season.