Ready to plant? Here are some tips

Start seeds of warm-season annuals and vegetables in a moist, soilless seed mix. These seeds should be started six to eight weeks before the last spring frost date, which is May 15 at the Chicago Botanic Garden.

Adjust your start dates accordingly if frost-free dates are earlier or later where you live.

A heat mat under the pots can help with germination. Transplant tiny seedlings into a "growing on" mix in slightly larger containers when they have two sets of true leaves. Gradually introduce the small plants to outdoor conditions before planting in the garden to acclimate them.

They can be replanted in containers or garden beds after the danger of frost has passed. Tomatoes do not like cold weather and will have stunted growth when conditions are too cold, so plant them at a later date if spring temperatures are cool.

• If you feed birds in your garden, be careful to prevent your dog from eating bird seed. The bird seed alone is probably not going to cause any problems unless he eats so much that his intestines become impacted.

Should a dog develop a large amount of gas in the stomach from the seeds fermenting, it can cause the stomach to bloat, which can lead to a condition in which the stomach twists on itself. This is a life-threatening condition that requires immediate emergency veterinary attention. Most dogs can pass small amounts of ingested bird seed.

Another potential problem is dogs may eat bird droppings that may contain salmonella bacteria along with the bird seed. Salmonella can cause severe digestive upset with lots of vomiting and diarrhea that can be fatal in very young or old dogs. The salmonella bacteria can also be passed on to you.

• March is a good month to control insects, such as magnolia scale, with an application of dormant oil. Verify that you have a problem insect before pursuing any controls. Do not apply treatments as a preventive measure.

Temperatures should be at least 40 degrees with no chance of freezing or rain within the following 24 hours. Avoid spraying on windy days to prevent any drift of the spray. As with any product, be sure to read the label to make sure the plants you are treating will not be damaged by the dormant oil spray.

Dormant oils can be very effective with minimal impact on the environment when used properly.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.