Read by Matilda Longbottom

I still remember the first time I knelt down to plant a packet of wildflower seeds in my garden. I scattered them like a child tossing confetti, then promptly buried them under a careful layer of soil—only to learn later that many of those tiny seeds had wanted nothing more than a little light and a gentle press into the earth.

Seed starting is one of those deceptively simple parts of gardening. You press a seed into soil, water it, and wait. But over the years, I’ve come to appreciate the small wisdoms that live in those early steps—like knowing which seeds need the quiet dark of soil to wake up, and which ones prefer the kiss of sunlight to begin their journey.

So whether you’re sowing vegetables, herbs, fruits, flowers, or even the seeds of future shrubs and trees, here’s what I’ve learned about which seeds to cover—and which ones to leave be.

Why It Matters

All seeds need moisture, warmth, and oxygen to germinate. But for some seeds, light is also a key factor. Some seeds must be exposed to light in order to sprout, while others require the darkness of soil coverage.

In general:

• Small seeds often require light and should be left uncovered or barely dusted with soil.
• Larger seeds contain more energy and are better equipped to push through soil, so they should be buried according to their size.

Planting too deep can prevent seedlings from reaching the surface. On the other hand, planting too shallow can dry out seeds or leave them exposed to birds or the wind.

Seeds That Should Be Covered with Soil

These seeds germinate best in darkness and typically benefit from a planting depth of about two to three times their diameter. This is of course not a comprehensive list but includes many popular plants.

Vegetables

• Beans (bush, pole, lima)
• Corn
• Cucumbers
• Melons (cantaloupe, watermelon)
• Peas
• Pumpkins
• Squash (zucchini, winter, summer)
• Beets
• Carrots
• Chard
• Radishes
• Turnips
• Kale
• Spinach
• Lettuce (very light cover or none)

Fruits

• Cantaloupe
• Watermelon
• Ground cherries (physalis)
• Passionfruit (scarification often needed)
• Papaya
• Loofah (technically a gourd, often grown like fruit)
• Strawberry (from seed, needs light cold stratification but light soil cover)
• Tomato (botanically a fruit, often listed with vegetables)
• Huckleberry
• Gooseberry (requires cold stratification, then soil cover)

Herbs

• Parsley
• Cilantro
• Fennel
• Chives

Flowers

• Marigolds
• Zinnias
• Sunflowers
• Nasturtiums
• Cosmos
• Morning glories
• Calendula

Ornamental Bushes & Shrubs (from seed)

• Butterfly bush (Buddleia)
• Forsythia
• Elderberry
• Hydrangea (some varieties)
• Rugosa rose

These seeds are typically larger and may take longer to germinate but benefit from the steady moisture and insulation of being covered with soil.

Seeds That Should Not Be Covered (Surface-Sown)

Some seeds are so small that even a thin layer of soil can prevent them from germinating. These seeds either require light or are simply too delicate to push through a layer of soil.

Vegetables and Herbs

• Lettuce (surface-sown or barely covered)
• Celery
• Basil
• Dill
• Oregano
• Thyme
• Lemon balm
• Marjoram
• Savory

Fruits (if grown from seed)

• Strawberry (especially alpine and wild varieties)
• Dragon fruit (pitaya)
• Kiwi (cold stratification often needed, then surface-sown)
• Fig (if growing from seed, requires light)
• Elderberry (requires light and stratification)
• Mulberry

Flowers

• Petunias
• Snapdragons
• Poppies
• Alyssum
• Impatiens
• Nicotiana
• Lobelia
• Coleus

Decorative Plants and Bushes

• Lavender
• Dusty Miller
• Ornamental grasses (many types)
• Echinacea (Coneflower, light cover or none)
• Bee balm (Monarda)
• Butterfly weed (Asclepias tuberosa)

Surface-sown seeds should be gently pressed into the soil to ensure contact but not buried. Keeping the soil consistently moist is critical, especially in the early stages of germination.

Special Considerations for Specific Plants

Tomato Seeds
Tomato seeds, though often thought of as vegetables, are botanically fruits. They are considered medium-sized seeds that should be covered with soil. Plant tomato seeds about 1/4 inch deep in a warm, moist medium. Once germinated, provide them with abundant light to prevent leggy growth.

Lettuce
Lettuce is unique—it benefits from light during germination but can also benefit from a very thin layer of fine soil or vermiculite. In cooler, moist conditions, many gardeners opt to leave lettuce seeds uncovered.

Fruit Seeds (Additional Notes)

• Stratification: Some fruit seeds (for example, apples, pears, and stone fruits) require a chilling period before planting. Check specific instructions based on the fruit species.
• Genetic Variability: Keep in mind that seeds from many fruit trees may not produce offspring identical to the parent plant.
• Pre-Treatment: Clean the fruit seeds thoroughly to remove any fruit residue that may promote mold growth when planted.

General Planting Depth Guide

Use this as a general rule when in doubt:

• Tiny seeds (herbs, flowers): surface-sown or covered with 1/8″ of soil
• Medium seeds (lettuce, carrots): 1/4″ deep
• Large seeds (beans, squash, sunflowers): 1/2″ to 1″ deep

Always refer to seed packets when available, as they provide the most accurate recommendations for that specific variety.

Taking the time to consider how each seed prefers to be planted can have a lasting impact on your garden’s success. Whether you’re sowing vegetables, herbs, flowers, decorative shrubs, or even fruit seeds, matching the planting method to the seed’s natural requirements gives it the best possible start.

By grouping your seed trays or garden rows and keeping a reference chart on hand, you can streamline your planting process and improve your chances of healthy germination. Consistent moisture, proper warmth, and careful attention to planting depth are the keys to transforming a collection of seeds into a flourishing garden.

What else would you like to add to the conversation? Shares your tips and tricks! ❖