Planting Timeline
Showing dates for Casper in USDA Zone 7
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Casper · Zones 5–11
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| Zone 5 | February – March | May – June | — | July – September |
| Zone 6 | February – March | May – June | — | July – October |
| Zone 7 | January – February | April – May | — | June – October |
| Zone 8 | January – February | April – May | — | June – November |
| Zone 9 | December – January | March – April | — | May – November |
| Zone 10 | November – December | February – March | — | April – December |
Complete Growing Guide
Start your Casper eggplant seeds indoors 8-10 weeks before your last expected frost date, as these Japanese beauties need a long, warm growing season. Sow seeds ¼ inch deep in seed-starting mix at 80-85°F for optimal germination, which typically takes 7-14 days. Keep seedlings under grow lights or in a south-facing window, maintaining temperatures above 70°F during the day.
Prepare your planting site by working 2-3 inches of compost into well-draining soil with a pH between 6.0-6.8. Casper thrives in rich, fertile ground, so don't skimp on organic matter. Choose the sunniest spot in your garden, as insufficient sunlight will result in poor fruit set and weak, spindly plants.
Transplant outdoors only after soil temperature consistently reaches 65°F and nighttime temperatures stay above 50°F. Cold soil will shock the roots and stunt growth permanently. Space plants 18-24 inches apart in rows 3 feet apart. Install sturdy stakes or cages at planting time, as mature plants can reach 3 feet tall and produce heavy fruit clusters.
Feed with a balanced fertilizer (10-10-10) at transplanting, then switch to lower nitrogen (5-10-10) once flowering begins to prevent excessive foliage at the expense of fruit production. Side-dress with compost monthly throughout the growing season.
Mulch heavily around plants to retain moisture and suppress weeds, keeping mulch 2 inches away from stems to prevent fungal issues. Casper needs consistent moisture but abhors waterlogged conditions - aim for 1-1.5 inches weekly through drip irrigation or soaker hoses.
Avoid the common mistake of harvesting too late. Unlike purple varieties, Casper's white skin makes it harder to judge ripeness, leading many gardeners to let fruits become oversized and seedy. In zones 7-9, provide afternoon shade during peak summer to prevent sunscald on the pale fruits.
Harvesting
Harvest Casper eggplants when fruits reach 4-6 inches in length and maintain their glossy, luminous white appearance. The skin should be firm but yield slightly to gentle pressure - avoid fruits that feel hard or show any yellowing, which indicates over-maturity and potential bitterness. Unlike purple varieties, Casper's white skin won't darken when ready, so size and firmness are your primary indicators.
Perform the fingernail test: gently press your thumbnail into the skin near the blossom end. If it leaves a slight indentation that springs back, the fruit is perfectly ripe. If your nail bounces off without marking, wait a few more days. If it sinks in easily, you've waited too long.
Harvest in the morning when fruits are fully hydrated and at their peak texture. Use sharp pruning shears or a knife to cut the stem ¼ inch above the fruit, rather than twisting or pulling, which can damage the plant and reduce future yields. Handle gently, as the pale skin shows bruises more readily than darker varieties.
Storage & Preservation
Store freshly harvested Casper eggplants at room temperature for up to 3 days for peak flavor and texture. For longer storage, refrigerate in the crisper drawer wrapped loosely in perforated plastic bags for up to one week. Unlike heartier purple varieties, Casper's delicate skin makes it more susceptible to chilling injury below 50°F, so avoid storing in very cold refrigerators.
For preservation, Casper's creamy texture makes it ideal for freezing after blanching. Cut into rounds, blanch for 4 minutes, then freeze on baking sheets before transferring to freezer bags. The mild flavor also excels in pressure-canned ratatouille or caponata. Avoid dehydrating, as Casper's high moisture content makes it prone to spoilage during the drying process. Consider fermenting small fruits whole in salt brine for a unique probiotic preserve that showcases the variety's naturally sweet flavor.
History & Origin
Casper eggplant originated in Japan, where white-skinned nasu (eggplant) varieties have been cultivated for centuries as prized ingredients in traditional cuisine. Japanese breeders developed this particular strain in the early 20th century, selecting for the distinctive ghostly pale coloration and exceptionally mild flavor that eliminates the bitter compounds found in many purple varieties.
The variety gained popularity among American gardeners in the 1990s through specialty seed companies focusing on Asian heirloom vegetables. Its name 'Casper' references the friendly ghost character, highlighting the fruit's luminous, almost supernatural white appearance that seems to glow in the garden.
In Japanese culinary tradition, white eggplants like Casper are considered more refined than purple varieties, prized for their ability to absorb flavors without contributing bitterness. This cultural preference drove centuries of careful selection, resulting in the sweet, creamy-textured fruits we grow today. The variety represents the pinnacle of Japanese eggplant breeding, combining visual beauty with exceptional eating quality.
Advantages
- +Never develops bitterness even when fully mature, unlike purple varieties
- +Stunning visual impact creates conversation pieces and premium market appeal
- +Exceptionally creamy texture that absorbs marinades and seasonings beautifully
- +Mild, sweet flavor appeals to eggplant skeptics and children
- +Luminous white skin shows no scratches or minor blemishes that would mar purple varieties
- +Produces consistently uniform, elongated fruits throughout the season
- +Heat-tolerant once established, continuing production through hot summers
Considerations
- -Requires longer, warmer growing season than many purple varieties
- -White skin shows sunscald damage more readily in intense afternoon sun
- -More expensive seeds due to heirloom status and specialized breeding
- -Delicate skin bruises and nicks more easily during harvest and handling
- -Typical heirloom disease susceptibility requires vigilant garden management
Companion Plants
Plant Together
Basil
Repels aphids, spider mites, and thrips while potentially improving eggplant flavor
Tomatoes
Similar growing requirements and can share support structures, both nightshades with compatible needs
Peppers
Fellow nightshades with similar soil and water requirements, can deter some common pests
Marigolds
Repel nematodes, aphids, and whiteflies while attracting beneficial predatory insects
Nasturtiums
Act as trap crops for aphids and cucumber beetles, drawing pests away from eggplant
Catnip
Repels flea beetles, aphids, and ants that commonly attack eggplant
Hot Peppers
Natural pest deterrent that repels many insects harmful to eggplant
Oregano
Repels aphids and provides ground cover while improving soil health
Keep Apart
Black Walnut
Produces juglone toxin that inhibits nightshade family growth and can kill eggplant
Fennel
Allelopathic properties inhibit growth of most vegetables including eggplant
Corn
Competes for nutrients and can harbor corn earworms that also attack eggplant
Pests & Disease Resistance
Resistance
Typical heirloom disease susceptibility, needs good garden hygiene
Common Pests
Flea beetles, Colorado potato beetle, aphids, hornworms
Diseases
Verticillium wilt, fusarium wilt, bacterial spot, phomopsis blight