“I want to try growing tomatoes in my garden this year and would like some advice on how to be successful.”
— Larry Zar, Highwood
There are some basic practices that you should follow to ensure your tomato growing success.
Garden centers now have many tomato plants for sale, so finding good quality plants should be easy. Certain tomato cultivars (meaning they have a certain, defined growing height) grow to 2 to 3 feet tall and generally don’t need staking—so good for small spaces and containers. They tend to produce many ripe tomatoes earlier in the season and at the same time with lower productivity in the second half of the season.
Indeterminate tomatoes will continue to grow tall and need cages or stakes. They produce fruit all summer and into the fall when frost kills the plants. Fruit production slows as the days get shorter and colder in the fall before a frost.
Look for tomato plants that have dark green leaves and are short and stocky with strong stems. They should not produce flowers or fruit unless they are established plants growing in a large container. I prefer growing old varieties because of the large number of different species. Plants dry out quickly indoors, so be sure to keep a close eye on watering them until you’re ready to plant them.
It’s very important to wait until temperatures remain consistently warm before planting tomatoes, as cold soil and air temperatures can dramatically affect their growth. Memorial Day weekend is generally a good time to plant tomatoes in the Chicago area, but be aware of the weather as the timing may be earlier or later depending on spring weather. I saw tomatoes for sale in late April and wondered how these plants have fared without the gardeners employing special growing techniques to compensate for the cold weather.
Tomato plants need to be in a bed with full sun for best results, as light shade will affect fruit production. I have successfully grown tomatoes in beds shaded in the morning with full sun in the afternoon. The soil should be well drained and supplemented with compost.
Plant the tomatoes deep by burying most of the stem. Remove any lower leaves that will be underground after planting. The plants form roots along the stem. Deep planting also helps stabilize any grafts that happen to be larger and scrawny. Make sure there is enough space – at least 60 cm – for each plant to develop, as many tomatoes grow large. Install tomato cages shortly after planting to protect and support the young plants.
Consider rotating cultures with unrelated ones to break insect and disease life cycles if you can. Peppers, aubergines, potatoes and other plants from the nightshade family are related to tomatoes and should therefore not be planted during crop rotation. This can be more difficult if you’re short on space, so choose your plants carefully and experiment with different combinations.
For more plant advice, contact the Plant Information Service at the Chicago Botanic Garden at email@example.com. Tim Johnson is Senior Director of Horticulture at the Chicago Botanic Garden.