Over-watered Garden tulip will develop yellow leaves. It is normal for yellow leaves to develop when Garden tulip has reached the end of their blooming period. However, if the leaves turn yellow before the flowers have bloomed, it is a sign of over watering.
If you water your Garden tulip too much, then try to ensure there is adequate drainage and do not give it any more water for a couple of days. You can mix some sawdust into the soil to absorb the moisture. If the situation continues to deteriorate after controlled watering, consider whether the seedpods have rotted. Try digging them up and checking whether they have changed color and become soft. Once you find severe decay, then you should promptly clean out these seedpods.
Under-watered Garden tulip actually looks similar to over-watered Garden tulip with their yellow leaves. However, the stems will also droop and leaves will look smaller and will curl. You may also see some brown patches appear.
If you have given your Garden tulip too little water, then do not panic. It has a level of drought tolerance. Once you have realised, give it a good drink but do not saturate the surrounding soil. Just make sure it is moist.But do not give them too much and overwater them, you just need to let the soil to be mosit. Extended periods in water can lead to root rot and fungus growing on the bulb. The fungus can cause serious damage to the bulb which is noticed through spots that appear on the leaves and buds. The tips of the leaves may also discolor and die.