Why Do Seeds in the Garden Grow Just As Fast As a Transplant?
- Plants which are started indoors or in greenhouses and transplanted later will experience some level of transplant shock. Transplant shock is caused by a combination of factors. Root damage during transplanting, roots which have dried out during transplanting, sudden increase in environmental factors like increased intensity of sunlight, wind and temperature can all induce transplant shock. Transplant shock can induce a period of dormancy in plants lasting as long as several weeks, and in severe cases the plant may die. This tends to cancel the advantage gained by using transplants. Hardening off of seedlings by placing them outside for short periods daily for a week or two prior to transplanting can help alleviate this.
- Plants intended for transplant may be hardened off prior to planting in an effort to reduce transplant shock. This involves placing the plants outside for short periods on a daily basis for a week or two to acclimatize the plants to the more harsh and intense outdoor conditions. This can help reduce transplant shock and help the plants to resume growth quicker.
- Plants which are chosen for their flowers are often selected as transplants with flowers on them already. This is a common mistake, as newly transplanted plants need a period of root-building in order to become well established. Plants with flowers already blooming have switched their growth habit to flower production and may not grow any larger after transplanting. This can also cancel part of the advantage of an early start. Choose plants for transplanting which have not yet begun to flower.
- Soil conditions can also affect the comparative rates of growth of transplants and seeds. Growers often place transplants into the garden too early. These plants may die in extreme cases. Other plants simply will not grow until conditions warm sufficiently. Plants started from seed will not germinate until conditions are right for their growth. This is a built-in regulator of when to start seeds. Plants started from seed this way have an advantage over transplants because they do not germinate until the right environmental conditions are met, and transplants may be recovering from dormancy or transplant shock.
- Soil quality can also affect the rate of growth of direct-seeded plants and transplants. Transplants are generally started in a small pot filled with a seed-starting mix which may not be as rich as good garden soil. Transplanted plants must spend a period of time after transplant establishing new roots. Plants started from seed have unlimited room to grow a vigorous root system and are not confined by small pots. The soil in a garden with good, rich organic content will contribute to more rapid plant growth than typical seed-starting mixes. This can give direct-seeded plants an advantage over transplants.
- Many growers prefer to use methods to protect direct-seeded plants to extend the growing season, rather than relying on transplants. Cold frames, essentially miniature greenhouses, are one popular method. Cloches, which are even smaller, single-plant miniature greenhouses are another. Some growers use plastic to cover a series of curved hoops placed along a whole row of plants. Some growers even use underground heating methods such as electric elements, hot water pipes or rotting manure to heat the ground, allowing them to start seeds directly in the garden much earlier than would otherwise be possible.