How to Grow: Side Dress Fertilizer

Listen to this podcast on how to apply fertilizer as a side dressing in summer and which plants need it.


It’s been an interesting summer so far. Lots of rain, humidity and not necessarily high temperatures. But, the vegetables are still growing and now is a time to give them a little mid summer boost.

Many gardeners forget about side dressing. We may be diligent about amending the soil in spring, but plants need fertility throughout the growing season. An addition of compost, organic granular fertilizer or liquid fertilizer can help keep the fruit production coming. Give each plant a handful of compost, tablespoon of an organic 5-5-5 fertilizer or a cup full of an organic liquid fertilizer. Add the dry fertilizers 3 to 6 inches from the plant edge.

All plants aren’t created equal when it comes to side dressing. Legumes, such as beans and peas, generally don’t need any extra help. Quick maturing crops, such as radishes, arugula, and baby greens, just need good fertility at sowing. They’ll be finished quickly so don’t need more fertilization. Leafy green vegetables, such as lettuces, basil, kale, swiss chard and collards, will benefit from a quick acting liquid fertilizer such as fish emulsion or compost tea. Long season crops or ones that are heavy feeders, such as tomatoes, peppers, squash, cucumber, corn and melons, will need a boost of compost or a balanced organic granular fertilizer, to help them along.

The timing is important, too. Vining crops, such as cucumber and winter squash, should be given a side dressing when they start to flower. Tomatoes, peppers and eggplant when the first fruits are setting. Broccoli family crops about one month after planting. Beets and carrots after they’re thinned. Don’t add too much nitrogen to any of these crops or you’ll get lots of green growth with few roots or fruits.

Excerpted from the Vermont Garden Journal on Vermont Public Radio.