Nasturtiums are popular annual plants cherished for their vibrant, trumpet-shaped flowers and attractive, lily pad-like foliage. These fast-growing plants (Tropaeolum majus) are relatively easy to cultivate, making them a favorite for gardeners seeking quick color and edible flowers. While many plants tolerate being moved from a pot to the garden with little fuss, successfully transplanting nasturtiums requires specific, careful preparation and handling. The answer is yes, but only when specific conditions are met to protect their delicate root structure.
Understanding Nasturtium Sensitivity
The main challenge in moving a nasturtium plant stems from its extremely fragile root system and its growth habit. Unlike plants that develop a dense, fibrous root ball, nasturtiums tend to grow a primary, brittle taproot structure. This central root is highly susceptible to damage when disturbed, which can quickly lead to a condition known as transplant shock.
Transplant shock occurs when the plant’s roots are damaged, hindering their ability to absorb water and nutrients. This stress often manifests as wilting, yellowing leaves, or stunted growth. To mitigate this risk, transplant nasturtiums when they are very young seedlings, ideally with only their first set of true leaves. Starting seeds in biodegradable pots, such as peat or coir containers, is the most effective strategy because the entire container can be planted directly into the soil.
Preparing for a Successful Move
Preparation is the most important step for minimizing the stress of relocation. If seedlings were started indoors, they must first be “hardened off” by gradually exposing them to outdoor conditions over 7 to 10 days. This slow exposure to wind, sunlight, and fluctuating temperatures toughens the plant’s cell structure, helping it withstand the move.
Before any digging begins, water the plants thoroughly the day before the scheduled transplanting to hydrate the roots fully. Choose a time for the move when temperatures are cooler, such as a cloudy day or late in the afternoon, to reduce immediate moisture loss from the leaves. In the new garden location, dig the planting hole first, making it twice as wide as the current root ball but no deeper.
When removing the plant, keep the root mass completely intact without disturbing the clinging soil. If the plant is in a plastic container, gently tap the sides to loosen the soil and invert the pot, catching the root ball carefully. For plants already in the ground, use a hand trowel to dig widely around the base, lifting out the entire clump of soil to preserve the delicate root hairs. Place the intact root ball immediately into the prepared hole and backfill gently with soil.
Immediate Post-Transplant Care
Once the nasturtium is in its new home, immediate, deep watering is required to settle the soil and eliminate air pockets around the roots. This initial watering should soak the area thoroughly, encouraging the roots to establish contact with the surrounding earth. Avoid overhead watering, which can damage tender new stems and promote fungal issues.
For the first two or three days after transplanting, provide temporary shading to shield the young plant from intense, direct sunlight. This measure significantly reduces transpiration (the loss of water vapor from the leaves), helping the stressed roots catch up with moisture demands. Maintain consistently moist, but not saturated, soil for the next few weeks as the plant acclimates.
Monitor the plant daily for signs of wilting or discoloration. Avoid fertilizing immediately after transplanting, as the high salt content in most fertilizers can further stress the recovering roots. Wait until the plant shows clear signs of new growth before introducing any low-nitrogen feed, since excessive nitrogen promotes leaves over flower production.
Why Direct Seeding is Often Recommended
Despite the possibility of successful transplanting, direct sowing is the simplest method for growing nasturtiums. Seeds germinate easily and quickly, typically sprouting within 7 to 14 days when planted directly into the garden soil after the danger of the last frost has passed. Direct seeding completely bypasses the risk of root disturbance and transplant shock.
This method allows the plant to develop its taproot naturally and unimpeded, leading to a stronger, more vigorous plant. By skipping the indoor starting process, gardeners avoid the delicate sequence of hardening off and careful transplanting. Direct sowing ensures a smoother transition and a much higher rate of success for a healthy, blooming display.