What is Catmint and Why Grow It From Seed?
Growing catmint from seed is a straightforward and economical method to establish these beloved, aromatic plants in your garden. Catmint, scientifically known as Nepeta, is famed for its drought tolerance, low maintenance, and the delightful attraction it holds for bees, butterflies, and, of course, cats. Starting from seed allows you to cultivate a wider array of varieties and enjoy the satisfaction of nurturing plants from their earliest stages, often at a fraction of the cost of purchasing established plants. These hardy perennials are a valuable addition, providing long-lasting blooms and a beautiful scent that enhances any garden space, much like the dependable flowering of perennials such as hostas or the enduring bloom of certain salvias.
- Catmint from seed is cost-effective.
- Attracts pollinators like bees and butterflies.
- Drought-tolerant and low-maintenance.
- Offers long-lasting blooms and fragrance.
The appeal of Nepeta extends beyond its charm to cats; gardeners appreciate its resilience. While many gardeners opt for division of established clumps for propagation, starting catmint from seed provides an accessible entry point for beginners. It opens up a world of different Nepeta cultivars, some of which may be less commonly found as young plants in garden centres. The journey from a tiny seed to a flourishing plant is immensely gratifying, and the resulting catmint will offer blooms for months, a trait shared with plants like agapanthus which require specific timing for division and feeding to thrive.
The Benefits of Sowing Catmint Seeds
Opting for catmint from seed offers a multitude of advantages. Primarily, it significantly reduces the expense compared to buying mature plants. A single packet of seeds can yield a substantial number of plants, ideal for filling large borders or creating dense drifts of colour and fragrance. Furthermore, sowing seeds allows for greater control over the plant's genetic makeup, enabling you to select specific cultivars known for particular traits like flower colour, plant habit, or bloom duration. This method also provides an early start on the gardening calendar, giving seedlings a head start indoors before the final planting outdoors. Unlike some plants that flower sporadically, catmint typically offers a consistent display, adding to its garden value.
The inherent hardiness of catmint means it is relatively forgiving, even when started from seed. Once established, it requires minimal fuss, preferring well-drained soil and a sunny position. This resilience makes it a superb choice for sunny, drier borders where other plants might struggle. It’s a plant that actively contributes to biodiversity, acting as a magnet for beneficial insects, which is crucial for a healthy garden ecosystem. While other plants might demand constant attention, such as the specific timing for dividing agapanthus or the regular feeding of peonies, catmint largely looks after itself once its initial needs are met.
Starting catmint from seed is a highly rewarding endeavour for any gardener.
Getting Started: Sowing Your Catmint Seeds
When is the right time to sow catmint seeds? The process begins with understanding the needs of these seeds, which often benefit from light and specific temperatures to germinate successfully. You can sow them either indoors several weeks before the last expected frost, or directly outdoors after all danger of frost has passed and the soil has begun to warm. Success with growing Nepeta from seed hinges on providing the right conditions for germination and early growth. This requires careful attention to sowing depth, moisture, and temperature, much like nurturing the initial stages of other perennials such as foxgloves or lupins.
Indoor Sowing for Early Blooms
For an earlier flowering season, initiating your catmint seeds indoors is an excellent strategy. Begin about 6-8 weeks before your region’s average last frost date. Use trays or small pots filled with a good quality seed compost. Sow the seeds thinly on the surface, as they require light to germinate. Lightly press them into the soil to ensure good contact but do not cover them deeply. Mist the surface gently with water and cover the tray or pots with a clear lid or plastic wrap to maintain humidity. Place the containers in a warm spot, ideally around 18-24°C. A propagator can be beneficial, but a warm windowsill will also suffice. Keep the compost consistently moist but not waterlogged.
Germination typically takes between 7 to 21 days, though some varieties can take longer. Once seedlings appear, remove the cover and ensure they receive plenty of light. A south-facing windowsill is suitable, or supplemental grow lights can prevent them from becoming leggy. As the seedlings develop their first true leaves, they can be carefully pricked out and transplanted into individual pots. Continue to grow them on in bright, cool conditions until they are strong enough to be hardened off and planted out.
Harden off your young catmint plants gradually over a week to ten days before planting them into their final outdoor position. This involves placing them outside in a sheltered spot for increasing periods each day.
Direct Sowing Outdoors
If you prefer a simpler approach or are sowing in a milder climate, direct sowing catmint seeds outdoors is highly effective. Wait until the risk of frost has completely passed and the soil temperature has warmed up sufficiently, typically from late spring onwards. Prepare the planting area by clearing it of weeds and loosening the soil. Sow the seeds thinly over the prepared surface, again on bare soil, as they need light. You can lightly rake them in, ensuring they are not buried too deeply. Water the area gently but thoroughly. Keep the soil moist until germination occurs, which may take a few weeks. Thin the seedlings to stand about 20-30 cm apart once they are large enough to handle, depending on the mature size of the variety you are growing.
Ensure the planting site offers good drainage to prevent root rot.
Caring for Your Seed-Grown Catmint
Once your catmint seedlings have been transplanted into their permanent garden positions, they require minimal but essential care to flourish. The primary needs involve ensuring adequate sunlight, well-drained soil, and proper watering, especially during the initial establishment phase. These plants are remarkably drought-tolerant once mature, often outperforming less hardy plants in dry conditions. Providing the right environment from the outset will lead to healthier, more robust plants that are less susceptible to common problems, much like how understanding the needs of hostas can prevent issues like slug damage.
Sunlight and Soil Requirements
Catmint thrives in full sun, needing at least six to eight hours of direct sunlight per day for the best flowering and most compact growth. While it can tolerate partial shade, blooming will be less prolific, and the stems may become leggy and weak, requiring support. The soil should be well-drained; catmint detests sitting in waterlogged conditions, which can lead to root rot. Sandy or gravelly soils are ideal, but it will adapt to most garden soils provided drainage is adequate. If your soil is heavy clay, consider amending it with compost or grit to improve its structure and drainage. Unlike some plants that benefit from specific soil amendments, catmint is quite adaptable if waterlogging is avoided.
Watering and Feeding
Newly sown seeds and young seedlings require consistent moisture. Water gently but regularly to keep the compost or soil surface damp until germination and establishment. Once your catmint plants are established, their watering needs decrease significantly. They are highly drought-tolerant and prefer to dry out slightly between waterings. Overwatering is a common mistake that can be detrimental, leading to root diseases and reduced flowering. Established plants may only need watering during prolonged dry spells. Catmint generally does not require heavy feeding. In fact, over-fertilising can result in lush foliage at the expense of abundant flowers and can lead to floppy growth. A light application of a balanced, slow-release fertiliser in spring is usually sufficient. For exceptionally poor soil, a top-dressing of compost in spring can provide a gentle nutrient boost, similar to how one might consider feeding agapanthus when preparing them for the growing season.
Deadhead spent flower spikes regularly to encourage a second flush of blooms later in the season, and to keep the plant looking tidy.
Pruning and Maintenance
Pruning is key to maintaining a neat appearance and prolonging the flowering period of catmint. After the first main flush of flowers has faded, typically in mid-summer, cut the plant back by about half. This encourages a bushier habit and often prompts a second, though usually less prolific, display of flowers. It also prevents the plant from looking straggly as the season progresses. For varieties that tend to sprawl, a more rigorous prune might be needed. Deadheading individual spent flowers can also encourage more blooms. At the end of the growing season, you can trim the plant back further, or leave the dried stems for winter interest and to provide habitat for beneficial insects. Any weak or diseased stems should be removed promptly.
Well-drained soil is paramount for catmint's long-term health.
Troubleshooting Common Catmint Issues
While catmint is generally a robust and trouble-free plant, like any garden inhabitant, it can occasionally encounter issues. Understanding these potential problems and their solutions is part of successful cultivation, whether you started from seed or purchased mature plants. Many common issues stem from incorrect growing conditions, such as too much moisture or insufficient sunlight, which can stress the plant and make it more vulnerable. Being aware of these potential pitfalls allows you to address them proactively, ensuring your catmint remains healthy and attractive throughout the season, unlike plants that might present more complex problems, such as the specific concerns with lupins or the susceptibility of certain foxglove varieties to pests.
Pest and Disease Resistance
Catmint is renowned for its resistance to most common garden pests and diseases. Its strong fragrance is thought to deter many common garden nuisances. Aphids are rarely a significant problem, and issues like powdery mildew are uncommon unless plants are grown in overcrowded, poorly ventilated conditions or in excessive shade. If aphids do appear, a strong jet of water or a mild insecticidal soap is usually sufficient to control them. Unlike plants that commonly suffer from specific ailments, such as the potential for problems with salvias, or the need to guard hosta plants against slugs, Nepeta typically sails through the season unscathed.
The most common problem encountered with catmint is root rot, which is almost always due to poorly drained soil or overwatering. Symptoms include wilting, yellowing leaves, and stunted growth, even when the soil surface appears moist. If you suspect root rot, improve drainage immediately by amending the soil or, in severe cases, carefully transplanting the plant to a better-suited location. This is a crucial consideration, as it mirrors the importance of proper conditions for many other perennials, such as understanding the best time to split hostas to ensure their vigour.
Ensure excellent drainage to prevent root-related issues.
When Catmint Doesn't Bloom
If your catmint plants, especially those started from seed, fail to produce abundant flowers, several factors could be at play. Insufficient sunlight is the most common culprit; catmint needs at least six hours of direct sun daily to bloom profusely. If your plants are in too much shade, consider transplanting them to a sunnier spot. Overfeeding with high-nitrogen fertilisers can also cause excessive leafy growth at the expense of flowers. If you have fertilised heavily, reduce or cease feeding and focus on watering. Pruning at the wrong time can also affect flowering; while a mid-summer prune encourages rebloom, cutting back too early or too late can impact the main flowering period.
Another possibility is that the variety you have chosen might have a different flowering habit or a shorter bloom period. If you are comparing it to other plants, remember that, for instance, how long peonies last in bloom is very different from the extended flowering of catmint. Young plants grown from seed may also take a season to establish fully and reach their blooming potential. Patience is key; sometimes, a plant needs a full season to settle in before it truly shows its worth.
Overly Vigorous or Sprawling Growth
Some catmint varieties, particularly Nepeta x faassenii types, can become quite vigorous and sprawl. If your catmint is becoming too large or untidy, a simple prune can manage its size and shape. Cutting the plant back by about half in mid-summer, as mentioned previously, will prevent it from becoming a sprawling mass and encourage a denser, more floriferous plant. For varieties that are naturally very vigorous, such as some cultivars of Nepeta 'Six Hills Giant', this pruning is almost essential for maintaining a neat appearance in smaller gardens. This proactive maintenance prevents the plant from overwhelming its neighbours, a consideration relevant when planning garden layouts or when thinking about the spacing needed for plants that might divide expansively like agapanthus.
The true magic of catmint lies in its ability to thrive with minimal intervention once established.
Expanding Your Catmint Knowledge
While the core principles of growing catmint from seed remain consistent, there's always more to learn about this versatile plant. Understanding different varieties, companion planting, and propagation techniques can deepen your appreciation and enhance your gardening success. Each season offers new opportunities to observe how catmint interacts with its environment and other plants. For instance, observing how hosta plants flower or when to separate agapanthus can provide insights into the broader life cycles of perennials, and how catmint fits into this tapestry.
Exploring Catmint Varieties
The world of Nepeta is diverse, with numerous cultivars offering subtle variations in flower colour, size, and habit. While many seeds sold are for common types like 'Walker's Low' or 'Six Hills Giant', seed packets might also contain mixes or specific named varieties. Researching different Nepeta species and cultivars before purchasing seeds is worthwhile. Some are more compact, ideal for the front of borders or containers, while others form larger mounds. 'Cat's Pajamas' is a popular compact variety, and 'Little Trudy' offers a longer bloom time. The classic Nepeta x faassenii, often sold simply as catmint, is a reliable choice for mass planting. Each brings a slightly different character to the garden, much like selecting between different colours of foxglove or understanding the blooming cycle of lupins.
Companion Planting with Catmint
Catmint is an excellent companion plant for a wide range of garden flora. Its aromatic foliage and steady, blue-purple blooms complement many other perennials and annuals. It pairs beautifully with roses, as its scent can help deter aphids and its long blooming period provides continuous colour. It also works well alongside other drought-tolerant plants like lavender, echinacea, and ornamental grasses. Planting it near vegetables can attract pollinators to fruit-bearing crops and deter pests from leafy greens. Its low-growing habit makes it suitable for edging beds or naturalising in cottage garden schemes. Consider pairing it with plants that have different textures and bloom times, such as the bold foliage of hostas, the striking spikes of agapanthus, or the delicate flowers of peonies, to create visual interest throughout the garden.
Consider planting varieties of Nepeta with different growth habits together for a layered effect, or intersperse them with plants that offer contrasting flower colours like yellow foxglove or red salvias.
When to Divide Catmint
While starting from seed is our focus, it's useful to know about propagating established plants. Catmint can be divided, though it's not as frequently necessary as with some other perennials. If an established clump becomes overcrowded, or if you wish to propagate a specific variety, division is best carried out in early spring as new growth appears, or in early autumn. This process is similar to when to separate agapanthus or the best time to split hostas. Carefully dig up the clump, divide it into sections using a spade or trowel, ensuring each section has roots and shoots, and replant immediately. Water well after transplanting. Division helps rejuvenate older plants, encouraging stronger growth and more abundant flowering in the following seasons.
Researching specific Nepeta varieties can tailor your planting choices to your garden's conditions.