Marigolds are great companion plants that can be used to divert pests away from more important cropping plants. While they are annuals, marigolds are not very hardy. Always keep starting plants indoors to make sure you have enough for your needs.
Step 1: Plant Your Seeds
You can use seeds from the previous year’s plants or you can buy new seeds from a garden shop. It is best to plant the seeds indoors in pots to save any danger of a late frost killing them off. Marigolds germinate readily and grow quickly in a warm, dry atmosphere. It is usually safe to restrict your planting to one seed per pot because the failure rate is so low. Water each seed well after planting then wait for it to germinate.
Step 2: Transplant the Seedlings
Once you are sure you have had the last frost you can transplant the seedlings into your garden. If you are using them as companion plants, space them wide apart within the cropping plants. If you are planting them for their flowers, space them in rows about 6 inches apart.
Step 3: The Soil
While marigolds will grow in just about any soil they prefer rich and well-drained soil. To transplant them simply dig a hole about the size of the pot the seedlings are in. Tip the seedling and the soil into your hand and then transfer them into the hole. Tap down firmly and use any spare soil to fill gaps and spread around the seedling. Although an established marigold will tolerate a dry spell you should remember to water the seedlings once or twice a week.
Step 4: Mulching
Although marigolds are prolific growers and do keep pests down, they are not very robust when faced with weeds. It is a good idea to surround your marigold plants with a layer of mulch to keep the weeds down or plant them through a small sheet (9 inches square) of black polythene held in place by a few stones.
Step 5: Using Fertilizer
Once the marigolds start flowering they will bloom continually for several months. This can deplete the soil so it is a good idea to dig in a little fertilizer around the marigold roots to feed them.
Step 6: Slug Pellets
Marigolds are great at protecting other plants against insects. They have an aroma that is too strong for them. Unfortunately slugs love marigold leaves and can cause a lot of damage so it is a good idea to put a few slug pellets around the base of each marigold plant.
Marigolds are very attractive flowers and very easy to grow. Children especially like them because of the speed at which they grow and the large blooms that just keep on coming after the first ones arrive. The first frost kills off the plants very quickly so any plants that you have growing in pots should be brought into a frost-free area before winter really sets in.