Weather in the Garden
Objectives
Students will observe weather conditions in the garden over time.
Students will understand how weather affects planting times and plant growth.
Students will learn how weather recording tools are used to predict plant success.
Students will represent data in tables and graphical displays to describe typical weather conditions expected during a particular season.
Students will make a claim about the merit of a design solution that reduces impact of a weather-related hazard.
STEAM Connections & Kentucky Academic Standards
NGSS
Earth Systems and Physical Science - Weather and Climate - K-PS3-1, K-ESS2-1, 1-ESS1-2, 3-ESS2-1, 3-ESS2-2, 3-ESS3-1
Life Sciences - Interdependent Relationships in Ecosystems - K-LS1-1, K-ESS3-1, K-ESS3-3, 2-LS4-1, 3-LS4-4
Technology
Using tools: thermometer and computer for research
Math
Measurement and Data
ELA
Book connections and research
Our Seasons By Grace Lin
Notes & Activity Ideas
Temperature is a reliable indicator of success when planting a garden. Both air temperature and soil temperature need to be considered.
Review or introduce seasons, climate, and related vocabulary such as temperature, thermometer, freezing, air temperature, soil temperature, rain, drought, and rain gauge. Consider reading the book Our Seasons, by Grace Lin.
Prepare students by either teaching or reviewing “How to Use a Thermometer.” Young students may have difficulty reading the numbers and understanding the lines between numbers so consider using a digital thermometer.
Have a discussion with students about the seasons and ask when they think the weather is beginning to warm up? Ask when they see trees blooming? Before thermometers were available to most gardeners and farmers, they would follow the guide for planting by observing nature. Most of the time, if trees and some early flowers are blooming it is time to begin planting the garden! This may also be a great time to introduce The Farmer’s Almanac, which gives predictions on weather and when to plant a garden.
Remind students that when the temperature is 32 degrees F or lower, the air temperature is freezing. When it is too cold, seeds will not germinate and young plants may not survive. That is why it is important to understand what kind of weather is best for planting and growing gardens.
Have students track air and soil temperature (see Activity 5 of The Dirt on Soil for instructions) for several days in the spring to determine the best time for planting seeds. For a math extension, have students graph those temperatures and find the difference between the highest and lowest.
Planting and Soil Temperature
Vegetable seeds can be sown in the garden early in spring before the soil has warmed to optimal germination temperatures. If you sow early before temperatures are ideal, you cannot expect optimal germination.
Optimal germination and growing temperatures may not come until late spring or early summer. In regions where the growing season is short, waiting for optimal soil temperatures may not be practical or realistic. A 70 percent germination rate is often considered both practical and realistic.
(See seed viability extension at end of lesson.)
Minimum Soil Temperatures for Seed Sowing and Germination:
35°F: lettuce, onion, parsnip, spinach.
40°F: beet, broccoli, Brussels sprouts, cabbage, carrot, cauliflower, collards, Asian greens, Chinese cabbage, fava beans, kale, kohlrabi, mustard, arugula, radish, Swiss chard, turnip, pea, radish, rutabaga.
50°F: asparagus, celery, celeriac, corn, tomato.
60°F: bean, cucumber, eggplant, muskmelon, pepper, pumpkin, squash, watermelon.
Soil Temperature Needed for 70% Germination:
45°F: beets, lettuce, parsley, spinach.
50°F: broccoli, Brussels sprouts, cabbage, carrot, cauliflower, collards, Asian greens, Chinese cabbage, fava beans, kale, kohlrabi, mustard, arugula, radish, Swiss chard, turnip, pea, radish, rutabaga.
55°F: cabbage, corn, Swiss chard, tomatoes.
65°F: cucumbers, peppers.
70°F: beans, cantaloupe, melons, squash.
75°F: eggplant, okra, pumpkins.
Optimal Soil Temperature for Germination (near 100% germination):
65°F: parsnip.
70°F: spinach.
75°F: asparagus, lettuce, onion, parsley.
80°F: bean, carrot.
85°F: beet, cabbage, eggplant, pepper, radish, Swiss chard, tomato, turnip.
90°F: muskmelon.
95°F: corn, cucumber, pumpkin, squash, watermelon.
For flowers and other vegetables not listed, seed packaging will usually list optimum soil temperatures.
Old fashioned way to know when to plant - Workable Soil Test for Direct Seed Sowing and Transplants:
Before soil thermometers were used in gardens and farms, the common method of determining when to plant was soil workability.
The soil is workable and ready for seed sowing or planting if it passes the Workable Soil Test. Here’s the test: squeeze a handful of soil in the palm of your hand; when you open your hand if the soil remains a wet or very moist clump, it is not workable. Let the soil dry. If the soil crumbles from your hand with a touch, it is workable.
When the soil is workable in spring, you can:
· Direct sow: collards, kale, lettuce, parsnip, peas, radish, rutabaga, spinach, turnips.
· Transplant out: broccoli, Brussels sprouts, cabbage, onion.
Of course, once the soil is workable in spring, it will continue to warm.
difference on the thermometer, compared with the difference in how the temperature felt between inside and outside.
Weather and Temperature Extension for older students
When it comes to temperatures, nothing fascinates children more than what the temperature is like out of doors. Obtain a report on the yearly weather patterns in your city. The report should include average highs, lows and record-setting temperatures. Then, use that data to teach a math lesson. For example, tell the students what the average high and low temperatures are in your city each year, then ask the students to estimate what the record high in your city has been to date. Graph the responses and then see how far off or close to the mark the estimates were. Or choose a month and graph the average highs and lows, and then find the mean and median.
Seed Viability Activity
(This is a good opportunity to teach about doing a fair test. Keep the variables (conditions), the same for all parts of the germination test.)
Seeds are sometimes left over from previous seasons and may be donated to classes. It is often hard to know if the seeds are still viable – meaning, will they germinate? You may want to try this winter activity to test the seeds.
Materials: planting trays ( these can be purchased online or at garden centers or can be made using disposable trays filled with planting soil. If planting into a tray of soil, it is imperative that water does not accumulate and flood the soil. I suggest using peat pots or pellets. Seeds, Craft sticks for labeling, Water
Assemble trays for planting and prepare soil
Select 10 seeds (or any number you choose) to plant
Follow directions on seed packet for planting depth and plant seeds
Mark the tray with the craft sticks by writing the name of the seeds and the date they were planted. Use the other side of the stick to draw a picture of the plant for use when planting in the garden.
Water carefully and place in a warm place – preferably on a window sill or near a light source
Watch the seeds for germination.
When plants have germinated and are an inch or so above the soil line, count the number of plants. Using the number of seeds planted and the number of seeds that grew, determine the percentage of plants that grew. This number is the viability number. (If you planted 10 seeds and 7 came up, the viability rate is 70% and the seeds are likely to grow in the garden.)
Have the class determine if they feel it is worth the garden space and time to plant these seeds. Keep in mind that if it takes 7 – 14 days for specific seeds to germinate, the window for growth to harvest may not be long enough for a second planting.