Planting Perennial Herb Plants - Part 1
The best perennial herbs are year-round and long-lasting. In the typical Falls County, TX, climate, that means special attention to soil condition and watering schedules. The greatest news this month is that early Spring (March to April) is the best time to plant perennial herbs like rosemary, thyme, oregano, lavender, sage, mint, and lemon balm. Planting now will allow roots to establish in a still cool, moist soil before intense summer heat.
Fortunately for gardeners in Falls County, there is a class of herbs that thrives in drier conditions. These are the Mediterranean herbs and the common culinary varieties. Rosemary, thyme, oregano, lavender, and marjoram do well with little water once established. The soil must be extremely well drained especially for lavender and thyme varieties.
It is easy to overwater these perennial herbs. Water sparingly and mulch with rocks or gravel to help dry the immediate environment and combat the effects of high humidity.
Rosemary ‘Arp’ serves as a culinary herb, a fragrant hedge, or a container plant. ‘Arp’ is highly recommended for cold tolerance, as it can withstand freezing temperatures. Conversely, it is rarely bothered by pests and thrives in the hot, dry summers of Central Texas. In late Spring to early Summer, Rosemary ‘Arp’ produces clusters of light blue, tubular flowers that attract bees, butterflies, and hummingbirds, enhancing garden biodiversity.
Other rosemary favorites are ‘Miss Jessopp’s Upright’ and ‘Tuscan Blue’.
If starting from seeds, there is still time to transplant the seedlings into your larger pots or raised beds.
Use pots with drainage holes. If starting indoors, seed trays or small paper cups work well. A light, sterilized seed-starting mix (ideally a mix of peat moss and vermiculite/perlite) will ensure good drainage and root development. Premoisten the potting mix until it holds its shape but is not dripping. Sow seeds, covering them with soil to about twice their thickness. Place containers in a sunny, south-facing window. (The alternate method is “winter sowing”: containers are placed outside in a sunny spot, with milk jugs acting as mini-greenhouses, allowing seeds to germinate when they are ready.) Keep the soil consistently moist but not waterlogged.
Transplanting seedlings? Select an area in full sun (at least 6-8 hours) in well-drained, slightly alkaline to neutral soil. Raised beds help prevent root rot in otherwise heavy clay soil.
Rosemary requires little fertilizer; over-fertilizing can reduce flavor and oil concentration. Prune in Spring to maintain shape.
Perennial herb plants need water regularly during the first year to establish roots, then reduce watering significantly as they are drought tolerant. Perennial herb plants need 2 to 3 feet around them for mature growth.
The hardy Thyme thrives in the Fall but start it now. It is perfect for small spaces and can be sown and grown in containers or garden beds, following the same methods and watering as described for Rosemary. Thyme adds a lovely, aromatic flavor to a variety of dishes.
Oregano! An easy-togrow, hardy perennial in Falls County, Texas, thrives in full sun and welldraining soil. If oregano seeds were not started indoors 6-10 weeks before now, they can be directly sown now, since the soil is warm. Oregano likes raised beds or pots. Water Oregano regularly to establish, then let the soil dry out between watering. This will avoid root rot. Once it is established, oregano needs very little water! Cut back Oregano in late Spring to encourage fresh, bushier growth and keep it from becoming woody.
Lavender top choices are Spanish, Provence Goodwins Greek varieties. Lavender is planted similarly to oregano. They even thrive well together, even though Lavender is tall and Oregano grows low and wide.
Marjoram is closely related to oregano. Marjoram has a mild, sweet pine /citrus flavor. Oregano is savory, pungent, and spicy. Marjoram is planted similarly to Oregano.
Hard to keep track of which herb to water, when it was last watered, or how much? Keep track in a garden journal. A simple notebook will do.
Regular harvesting encourages more growth, so don’t be shy about picking those herbs when they’re ready. It’s a win-win with fresh herbs, while plants stay healthy and productive.
Happy gardening perennial herbs!
Next week, more perennial herbs: sage, mint, and lemon balm!
Photo by L. Estep