Actually, any time from mid- to late March is fine for potato planting.

Be sure to buy seed potatoes rather than using those bought for cooking. Seed potatoes are certified disease-free and have plenty of starch to sprout as quickly as soil temperatures allow.

Most seed potatoes can be cut into four pieces, though large potatoes may yield more, and small potatoes less. Each seed piece should be between 1.5 and 2 ounces to insure there is enough energy for germination. Each pound of potatoes should yield 8 to10 seed pieces.

Cut the seed 2 to 3 days before planting so freshly cut surfaces have a chance to suberize, or toughen, and form a protective coating. Storing seed in a warm location during suberization will speed the process. Plant each seed piece about 1 to 2 inches deep and 8 to 12 inches apart in rows.

Though it is important to plant potatoes in March, emergence is slow. We are often into mid- to late April before new plants poke their way through the soil.As the potatoes grow, pull soil up to the base of the plants.

New potatoes are borne above the planted seed piece, and we don't want sunlight hitting the new potatoes. Exposed potatoes will turn green and produce a poisonous substance called solanine. Keeping the potatoes covered will prevent this.

Herbicides for vegetables

Though mulches and hoeing are usually all that is needed for small vegetable gardens, homeowners with large areas may need the help of herbicides to keep ahead of the weeds. There is one pre-emergence and one post-emergence herbicide that can be used on home vegetable gardens.

The pre-emergence herbicide is trifluralin. Pre-emergence herbicides kill weed seeds as they germinate. They usually have no effect on weeds that have emerged. Therefore they must be put on either before weeds come up in the spring or after weeds have been physically removed.

The pre-emergence herbicide trifluralin is sold under the trade names of Treflan, Preen, Miracle-Gro Garden Weed Preventer, Gordon's Garden Weed Preventer Granules and Monterey Vegetable and Ornamental Weeder.

The post-emergence herbicide is sethoxydim. This product will only kill grasses; broadleaves are not affected. However, it can be sprayed directly over the top of many vegetables.

Sethoxydim is sold as Poast, Monterey Grass Getter and Hi-Yield Grass Killer. A second post-emergence herbicide called fluazifop-p-butyl is labeled for commercial growers as Fusilade, but I haven't found vegetables listed on the homeowner labels, "Over the Top Grass Killer" and "Grass-No-More." Still you can use it in the landscape shrub and flower beds.

Also, the other homeowner products mentioned above often do not have as many vegetables on the label as the commercial products. Even among the homeowner products with the same active ingredient, there may be slight differences among labels.

Check product labels to be sure the crop is listed. Also realize that many of the crops listed will have application restrictions. For example, trifluralin can be used on asparagus, but must be applied before spears emerge.

Frost-proof veggie plants

There are certain vegetables that can withstand cold spring temperatures as long as they have been toughened up by hardening them off. Usually you need about a week to harden off a plant.

Reducing watering and temperature is key to toughen up transplants. If possible, also move your transplants outside for a portion of each day.

Start by placing the transplants in a shady, protected location and gradually move them into a more exposed, sunny location as the week progresses.

Hardened-off cabbage, broccoli, cauliflower and onions can withstand temperatures near 20 degrees without being killed.

Lettuce plants are not quite as tough but will be OK of exposed to temperatures in the mid-20s.

Don't hesitate to put these plants outside on some of our warmer spring days.

Jim Hruskoci is a Hall County Extension specialist in horticulture.