What is the average temperature for plants

Cool-season crops can be planted when the soil and air temperatures are at least 40 degrees Fahrenheit. These crops are often further divided into hardy and semi-hardy categories, depending upon their ability to withstand cold temperatures.

Hardy vegetables tolerate cold temperatures the best—their seeds will germinate in cool soil, and seedlings can typically survive heavy frost. Plant these seeds or transplants two to three weeks before the date of the average last spring frost; they will grow in daytime temperatures as low as 40 degrees Fahrenheit.

Semi-hardy vegetables withstand light frost. These crops grow best when the minimum daytime temperature is between 40 and 50 degrees Fahrenheit and can be sown as early as two weeks before the average last spring frost. Some cool season crops fare better when direct seeded, while others can be started indoors. This chart outlines recommendations for popular crops:. Post Comment. This site uses Akismet to reduce spam.

Learn how your comment data is processed. Please check settings. All info is non specific and nothing speaks to specific on any of the stages. This info in an easily accessible format would be a godsend, especially for a new gardener that is lost like myself! Any guidance would be helpful. There are many variables that come into play when growing vegetables: soil composition and texture; soil pH and nutrient composition; weather air, and soil temperature; garden orientation, sun exposure, day length, and length of growing season; rainfall and irrigation—these are a few.

These factors and others affect nutrient uptake and plant growth. One chart that would speak to ALL of these growth influences from seed to harvest and to EVERY microclimate and garden would be all but impossible to compose.

Adding aged compost to your garden regularly will bring your soil pH to near neutral, that will allow for the uptake of most nutrients. Aged compost or commercial organic planting mix will also add a wide spectrum of nutrients to the soil; keeping the soil evenly moist will allow for the uptake of the nutrients.

To aged compost, you can add an all purpose organic fertilizer. Organic fertilizers break down slowly and feed plants over weeks and months.

Workable soil is no longer frozen and it is not too wet. To determine if the soil is too wet to work, squeeze a handful of garden soil in your hand. Workable soil should fall apart easily and not stay clumped together. If it sticks together the ground is too wet to work. Soil temperature also plays an important role. Some plants will tolerate cool soil, while others require warm soil. Measure soil temperature by inserting a soil thermometer about 4" into the ground. Take a measurement in the early morning and late afternoon to get a high and low for the day, then average the temperature readings.

Measure soil temperature on sunny and on shaded areas of the garden. Most potted perennials that have been acclimated can also be planted at this time. These plants are naturally sensitive to cool temperatures and are not a good choice for early spring planting. To get a jump on the growing season and to avoid cold, wet garden soil, try growing plants in hanging baskets, patio pots or other above ground containers. Flowering annuals can often be planted in containers above ground earlier in the season than those planted in the ground.

Soilless mixes are used in containers which tend to be warmer and drier than garden soil, especially if containers were recently filled with new growing media that was not kept outdoors over winter. However, air temperature should still be taken into consideration and tender plants should not be planted before the danger of frost has passed. Monitor the weather forecast for all flowers planted in early spring, and if a frost is predicted, cover tender plants with a sheet or cold protection crop cover commercially available for frost protection.

Without some sort of protection, you are always taking a chance when planting outdoors in early spring and occasionally plants will get damaged.

By choosing cool tolerant plants, acclimating plants, planting in workable soil, closely watching weather forecasts and providing extra protection when needed, you will minimize the risk of losing plants. The quantification of ageing and survival in orthodox seeds. Seed Sci. The germination rate was calculated by the inverse of. Seed germination and radicle growth of a halophyte, Kalidium capsicum chenopodiaceae. Cardinal temperature was calculated on the basis of the responses of the germination rate to temperature Taghvaei et al.

An intersecting-line model Al- Sobhi et al. The T base and T maximum were derived from the intersection of each regression line with the abscissa, and the T optimum was calculated from the intersection of the two linear regression lines of the germination rate at sub-optimal and supra-optimal temperatures Covell et al.

Treatment means were separated by Duncan's test in cases where the F value of the treatments was significant at a probability level of 0. The seeds germinated more rapidly at 30 o C than at other temperature treatments, during the first hours and reached a germination peak Figure 2 , and seed germination was slower at 20 o C than at other temperatures. The germination rate increased along with increasing temperature.

Figure 2 The trend of cumulative germination response to temperature at 24 hours intervals at 20 o C, 25 o C, 30 o C, 35 o C, 40 o C. Each point represents the mean of 4 replications 50 seeds. The highest seed germination rate 0. The germination rates were 0. The highest positive slope of germination was noted at 30 o C; however, it was reduced at 35 o C Table 3. The fitted regression line for the germination rate evidenced a positive slope between 20 o C and 30 o C and a negative slope between 30 o C and 40 o C.

The intersection of fit linear regression between 20 o C and 30 o C and between 30 o C and 40 o C with the abscissa showed a T base of The intersection of two linear regression lines of the germination rate at sub-optimal and supra-optimal revealed the optimal temperature of Figure 3 and Table 3.

Thumbnail Table 3 Equation calculated cardinal temperature for Calotropis procera seeds. Figure 3 Calotropis procera germination rate response to temperature in the Fars dune desert seed source. In the first hours, the response of the germination to temperature differed completely. The seeds germinated rapidly at 30 o C and then reached their peak of germination Figure 4 , and the percentage of germinated seeds was lower at 20 o C than at 25 o C and 30 o C.

Figure 4 The trend of cumulative germination response to temperature at 24 hours intervals. The germination rate indicated an increasing trend from 20 o C to 30 o C and then the germination rate decreased abruptly with increases in temperature.

The highest and lowest germination rates were noted at 30 o C and 35 o C, respectively Figure 5. The germination rate was 0. The drawn-to-fit linear scale to cumulative normal distribution evidenced a positive slope from 20 o C to 30 o C and a negative slope from 30 o C to 35 o C. The intersection of fit linear regressions between 20 o C to 30 o C and between 30 o C to 35 o C with the abscissa showed a T base of 20 o C and a T. The intersection of the two linear regression lines of the germination rate at sub-optimal and supra-optimal temperatures revealed the optimal temperature at Figure 5 Calotropis procera germination rate response to temperature in the Zahedan dune desert seed source.

Seed germination is a critical stage that is profoundly affected by environmental factors, particularly by cardinal temperature minimum, optimum, and maximum temperatures. Our results showed that Calotropis procera seed germination is affected by temperature.

Many authors have previously reported this in their studies Phartyal et al. Seed germination started at 22 o C and the germination rate increased with increasing temperatures, showing a positive linear relationship between tempera-ture and germination rate from 20 o C to 30 o C.

Then, germination rate decreased with increasing temperatures so a negative linear relationship was detected from 30 o C to 45 o C Figure 2 and 3. Taghvaei et al. When fitting the linear regression of the point germination rate at sub-optimal and supraoptimal temperatures, the base temperature and maximum temperature for C.

Predicting germination response to temperature: I. Cardinal-temperature models and subpopulation-specific regression.