Cool season vegetables for planting now

There are a large number of vegetables that can grow when soil temperatures rise above 50 degrees. Many of them do their best under cooler growing conditions. Hot weather will slow or even almost stop production. Many of the leafy vegetables such as lettuce, kale, rhubarb, as well as all of the Cole crops such as broccoli and cauliflower will “bolt” or flower and set seed when the weather gets hotter. So to get the most from the following crops, plant as soon as danger of frost is past. The average last frost date for Minot is May 15.

Remember in the case of legumes that it is advisable to use an inoculant with the seed. Legumes are plants of the pea and bean family. They have bacteria that live in their roots with allow them to take nitrogen from the air and store or fix it in nodules on their roots. The inoculant is sold as a dry powder. When you are ready to seed peas or beans, moisten the seed and sprinkle a small amount of the powder on the seeds. In this way it will be close to the seed and the young plant will be able to pick the bacteria up and use in its roots.

When a vegetable produces over a longer period of time such as greens (lettuce, kale), peas and rhubarb, you can help extend the harvest by picking the leaves or pods before they mature. This will keep the plants producing more greens and flowering to produce more pods. If allowed to “mature”, leafy vegetables will “bolt” sooner and peas and beans will slow or stop flowering and instead ripen the pods already formed.

Be sure that your garden has adequate phosphorous. This nutrient is important for root growth and development and flowering and seed set. If this nutrient is lacking, or if too much nitrogen is in the soil, there will be a disproportionate amount of vegetative (green, leafy) growth with little or no flower and fruit production. Soil testing your garden will tell you if you need to add nutrient(s) and how much to add.

The following plants will tolerate a light frost (30-32 degrees) and will benefit the most from early planting.

– Asparagus

– Beets

– Broccoli

– Brussels sprouts

– Cabbage (early planting)

– Carrots

– Cauliflower

– Swiss chard

– Collards

– Endive

– Horseradish

– Kale

– Kohlrabi

– Lettuce (leaf or head)

– Onion sets

– Peas

– Potatoes

– Radish

– Rhubarb

– Spinach

– Turnips

Don’t Guess, Soil Test!!!!!

Growing plants of any kind need a balanced blend of plant nutrients to be their best. Without knowing what is in your lawn or garden soil, it is only a guess as to what nutrients are needed to be added to your soil to meet their needs. In some instances, nutrients are applied that are not needed which become a problem rather than a solution. Over fertilization with nitrogen in vegetable gardens comes to mind. When this occurs in a vegetable garden, you may end up with HUGE tomato vines as well as other green vegetation on other vegetable, but have very few or any tomatoes or any edible parts of other vegetables..

To avoid this mistake, gardens and yards can be sampled by home owners and tested by the NDSU Soil Testing Lab. The tests they do are very accurate and give recommendations for nitrogen, phosphorous or potassium. If any are needed, recommendations for the correct amounts to add are given. The test also measures and reports salt levels in the soil, pH (acidity/alkalinity) of the soil, and organic matter levels.

All NDSU Extension Offices have the soil sample bags and information sheets to complete and submit to the lab. The information sheets give instructions on how to sample your soil as well as where to submit the sample(s).

To pick up the soil test bags and sheets, visit the Ward County Extension Office in the Ward County Administration Building, 225 3rd Street SE, in Minot. Or call 857-6444 to request them and they will be mailed out to you.

Ken Eraas is horticulture assistant with NDSU Extension Service/Ward County. He can be reached at