Best Grow Lights for Seed Starting

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Seedlings on a windowsill often stretch toward the light and flop over. A grow light fixes that. It is probably the single biggest upgrade you can make to your seed starting setup.

Why a window is often not enough

In winter and early spring, daylight is short and weak. Even a south-facing window may not give enough intensity for tomatoes and peppers. Seedlings stretch and become pale and leggy.

Types of grow light

• LED. Efficient, runs cool and lasts a long time. This is the most popular choice today. Look for full-spectrum white LEDs.
• Fluorescent (T5). A proven, affordable option that is still widely used by home growers. Needs more space and bulbs wear out sooner.
• Regular household bulbs. Not recommended. They usually do not give enough light for seedlings.

What to look for

• Full-spectrum white light. It makes it easy to see your plants' true color and health.
• Enough coverage. The fixture should be at least as long as your tray, so seedlings at the edge get light too.
• Adjustable height. You will need to raise the light as seedlings grow. Chains or adjustable stands help.
• A plug-in timer. It makes day length automatic and consistent.
• Easy to link several fixtures. Useful if you plan to add trays later.

How far above the plants?

Follow the manufacturer's guidance, because it depends on the power of the light. As a general idea, small LED strips and T5 fixtures often work best a few inches above the seedlings, while stronger panels need more distance. Watch your plants: if they stretch toward the light, move it closer. If leaves look bleached or scorched, move it back.

How many hours per day?

Most seedlings do well with about 14 to 16 hours of light, then a dark period. Plants need darkness too, so do not leave lights on all day and night. A timer takes care of this.