Culinary Plants

The culinary plants Raintree carries exist in a different category from the typical kitchen-garden annual. These are perennial plants — often long-lived shrubs, herbaceous perennials, or woody specimens — that deliver flavor year after year once established. They are grown not for a single-season harvest but as permanent features of an edible landscape, each producing something that is genuinely better at home than anything available commercially.

Real wasabi — the actual rhizome of Eutrema japonica, grated fresh — is almost never what's served in a restaurant; nearly all wasabi paste sold in North America is horseradish-based. Growing your own means tasting the real thing. Fresh-processed tea from home-grown Camellia sinensis, harvested from the same bush season after season, bears little resemblance to commodity tea bags. Mioga ginger buds, used in Japanese cuisine for centuries, are essentially unavailable at retail in most of the US. Capers pickled from fresh-harvested buds have a brightness that bottled product rarely matches. The gap between what you can grow and what you can buy is at least as wide for culinary plants as it is for tree fruit.

These plants also tend to be low-maintenance once established. Rosemary thrives on neglect in well-drained soil. Lavender tolerates drought. Tea camellias, once past their first year or two, ask very little and reward patience. Getting the fundamentals right at planting — site, soil drainage, appropriate zone matching — is the primary investment required.

Herbs in Raintree's catalog are perennial or semi-perennial plants sold as started plants — not seeds — giving home growers an immediate, established specimen ready to harvest from in the season of planting. Several of the varieties Raintree carries are named cultivars selected specifically for culinary performance, not simply botanical species. This distinction matters: 'Spice Island' rosemary, for example, is chosen for its resinous oil content and flavor intensity, not just its growth habit.

Rosemary — Salvia rosmarinus

Rosemary (formerly classified as Rosmarinus officinalis, reclassified into Salvia by the Royal Botanic Gardens, Kew in 2017) is a drought-tolerant, evergreen Mediterranean shrub that is among the most reliable culinary plants a home grower can establish in Zones 7–10. It requires excellent drainage above all else — rosemary will tolerate dry, poor, rocky soil far more easily than it tolerates wet roots or standing water in winter. Full sun (6+ hours) is essential for best oil development and culinary quality (NC State Extension; UC ANR).

Raintree carries three rosemary selections:

• Spice Island Rosemary — an upright, strongly aromatic variety prized for bold culinary flavor; grows to approximately 4 feet tall; overwinters well in Zone 7 and warmer.
• Irene™ Rosemary — a trailing habit variety suited to cascading over walls, containers, or slopes; same culinary quality with a more prostrate form.
• Rosemary 6-Pack Bundle — a mixed bundle including Spice Island and Irene varieties, offering a 10% savings over individual plants.

This group covers plants grown primarily for their roots, rhizomes, or shoots — harvested whole or processed for flavor, not used as leafy herbs. Several of these are among the most unusual offerings in the Raintree catalog, either because they require very specific growing conditions (wasabi), because they fill a genuine gap in what's commercially available (mioga ginger), or because they are simply rare in US home gardens despite a long culinary history elsewhere (Chinese toon).

Culinary Ginger (Indoor) — Zingiber officinale

Common culinary ginger is a tropical rhizomatous perennial native to Southeast Asia. It is the ginger of commerce — the root sold in every grocery store — and when grown at home and harvested young, it produces rhizomes that are more tender, juicier, and milder than the mature, fibrous product found at retail. The outer skin rubs off easily on young homegrown rhizomes. Leaves and stalks are also edible and flavorful in teas and cooked dishes (Raintree Nursery product description; University of Florida IFAS Extension).

Mioga growing notes: Plant in partial to full shade — mioga performs best without direct afternoon sun. Soil should be rich in organic matter and well-drained; amend at planting with 2–3 inches of compost. Plants die back to the ground each winter and re-emerge reliably in spring; apply a 3–4 inch mulch layer in fall to protect the rhizome in colder zones. Harvest flower buds in late summer before they fully open, when they are most flavorful. Plants spread slowly by rhizome over time, eventually forming a useful ground cover in a shaded area.

Wasabi — Eutrema japonica (syn. Wasabia japonica)

Wasabi is among the most coveted — and most challenging — culinary plants a home grower can attempt. The plant is a semi-aquatic perennial native to mountain stream margins in Japan, grown for its thickened stem (rhizome), which is grated fresh to produce the intensely pungent condiment essential to Japanese cuisine. Virtually all "wasabi" served in restaurants in North America is a paste made from horseradish, mustard, and green dye — not actual wasabi. The real thing, grated fresh from the rhizome, has a heat that is sharp but short-lived, with floral complexity that horseradish entirely lacks (Japan Wasabi Association; University of Vermont Extension).

Raintree carries two wasabi options:

• Wasabi (Eutrema japonica) — the standard species offering, semi-aquatic, grown for the classic rhizome and ornamental rounded leaves.
• Mazuma Wasabi (Wasabia japonica 'Mazuma') — a named variety selected for its enlarged rhizome; slightly more productive under garden culture than the straight species.

Wasabi's requirements are specific and non-negotiable:

• Temperature: Cool — ideal range is 40–70°F. It does not tolerate heat. Temperatures below 27°F can kill the plant; frost protection is advisable in borderline zones.
• Light: Shade to partial shade — wasabi evolved under the forest canopy along streamsides and is damaged by direct summer sun.
• Water: Consistently moist soil with excellent drainage; never waterlogged. The highest-grade wasabi is grown in flowing water (semi-aquatic culture), but it grows well in garden soil or containers with consistent moisture and good drainage.
• Soil: High in organic matter; well-drained; pH 6.0–7.0.
• Planting: The crown must remain above the soil surface when planted.
• Pests: Slugs — monitor and control, particularly in the PNW.

All true tea — green, white, oolong, and black — comes from the leaves of a single species: Camellia sinensis. The different tea types are not different plants; they are the result of different processing methods applied to leaves harvested from the same evergreen shrub. Green tea is made from minimally processed fresh leaves (heat-fixed to stop oxidation); white tea from young buds and leaves dried with minimal processing; oolong from partially oxidized leaves; black tea from fully oxidized leaves (NC State Extension; Penn State Extension; University of Florida IFAS).

Growing tea at home puts the grower in control of what may be the most variable stage in tea production: harvest timing, leaf selection, and processing. A spring flush of young leaves from a home-grown C. sinensis, processed the same afternoon and brewed the following day, produces a cup that is genuinely different from anything available commercially — not because it is necessarily better, but because it is genuinely fresh and reflects the specific growing conditions of that garden.

Tea plant varieties at Raintree

Raintree carries three Camellia sinensis varieties, each suited to slightly different climates and production goals:

Growing tea — site and soil

Camellia sinensis prefers a site with 6+ hours of sun, though it tolerates partial shade (and, unlike many Camellia species, handles more sun than is typically associated with camellias). Soil pH is critical: tea plants require acidic soil in the range of 4.5–6.0, with 5.0–5.5 optimal for most cultivars (NC State Extension; Penn State Extension). This is more acidic than most home garden soils — test before planting. Amend with elemental sulfur to lower pH in alkaline soils; peat moss or composted pine bark incorporated at planting helps maintain acidity. Tea plants will show yellowing (chlorosis) in soils that are too alkaline. Well-drained soil is essential; they will not tolerate waterlogged roots.

Established plants are moderately drought-tolerant but produce better with consistent moisture through the growing season. A 2–3 inch mulch of wood chips or pine bark helps maintain soil moisture, moderates root zone temperature, and gradually acidifies the soil as it breaks down — an ideal mulch for this species.

Harvesting and processing

The harvest unit for tea production is the "flush" — the new growth at the tip of each branch. For green and white tea, harvest the terminal bud plus the two youngest leaves below it (the traditional "two leaves and a bud" standard). For oolong and black tea, a slightly older third leaf may be included. Harvest by pinching the tip flush between thumb and forefinger; this stimulates additional lateral growth and subsequent flushes. The first spring flush, from late March through April in most US climates, typically produces the highest-quality leaves (Penn State Extension).

Tea plants should not be heavily harvested until they are at least 3 years old and well-established. In the first two years, allow the plant to build size and root system; light harvesting of a few tips to taste is acceptable but should not stress the plant.

Capers are one of the great gap-fillers in the home culinary garden — they are widely used but essentially never grown outside of Mediterranean climates. The caper (Capparis spinosa) is a sprawling, semi-evergreen Mediterranean shrub that produces small flower buds on first-year branches from May through October. These buds are harvested before they open, brined in salt and herbs, and become the capers of commerce: pungent, tangy, with a flavor that bridges mustard and pepper.

If left unpicked, the buds open into showy, pinkish-white flowers with striking long lavender-colored stamens — one of the more beautiful blooms in the edible garden. The plant has real ornamental value even when not in production; the large, fragrant flowers open each morning and close in the afternoon throughout the long bloom season (Raintree Nursery product description; Mediterranean Herbs, University of Florida IFAS).

Raintree carries Spineless Caper (Capparis spinosa var. inermis), the spineless form of the common caper bush. This variety lacks the sharp stipular spines found on the standard species, making harvest and general handling considerably easier. It is self-fertile — no pollinizer required.

Zone requirements and cold hardiness

The caper bush is a Mediterranean plant and reflects that origin in its requirements and limitations. It is hardy outdoors to approximately 18°F and is rated for USDA Zone 8 and warmer as an outdoor perennial. In Zones 7 and colder, it must be grown in a container and overwintered in a frost-protected but cool location (unheated greenhouse, garage, or similar) when temperatures threaten to fall below 18°F (Raintree Nursery; NC State Extension).

The caper bush's heat and drought tolerance are exceptional — it evolved in the rocky limestone hillsides and cliff faces of the Mediterranean basin, where summer heat is intense and rainfall essentially stops for months. This makes it well-suited to hot, dry garden conditions where other culinary plants struggle.

Site, soil, and growing notes

Capers demand conditions that are the near-opposite of most culinary plants:

• Sun: Full sun — the more heat accumulated, the better
• Soil: Dry, well-drained, alkaline to neutral — sandy or gravelly soils are ideal; heavy clay or poorly draining soils will kill the plant; pH 7.0–8.0 preferred
• Water: Low — overwatering is the primary cause of failure. Established plants are highly drought-tolerant and should be watered only when soil is completely dry. Water is more critical in the first season of establishment.
• Pot culture: Excellent in containers; use a fast-draining, gritty mix (equal parts potting soil and perlite or coarse sand); ensure the container has generous drainage holes. Do not allow containers to sit in saucers that collect water.
• Size: Arching stems grow to approximately 3 feet tall with wider spreading habit

Despite the wide range of plants in this guide, several fundamentals apply broadly. The most important: nearly every culinary plant listed here will tolerate imperfect fertility far better than it tolerates poor drainage. Waterlogged roots are the leading cause of failure for rosemary, lavender, capers, wasabi (in excess), ginger, and tea camellias. Getting drainage right at planting — whether by choosing the correct site, building raised beds, or using fast-draining container mixes — prevents the majority of losses.

Before planting any of these species, conduct a simple drainage test: dig a hole 12 inches deep, fill it with water, and observe how quickly it drains. If water remains after 1 hour, drainage is inadequate for rosemary, lavender, sage, and capers (plants requiring the driest conditions). Plants like lemongrass, mioga ginger, and tea camellias tolerate more consistent moisture but still should not sit in standing water.

pH by plant group