Grass seed with 17 nitrogen and bulbs

(Question)

Over the years I have planted daffodil and crocus bulbs in my lawn for quite a spring display. Just recently my husband put grass seed on the lawn and it contained nutrients that turned out to be nitrogen 17. It has rained several times since. What can I do ? I realize that level of nitrogen encourages leaf growth and root rot but no flowers for next year. Is there a solution? Thank you.

(Answer)

Thank you for contacting Toronto Master Gardeners with your question about nutrients affecting your lawn and bulb planting.  You mention the lawn received grass seed with nitrogen 17. Unless additional chemicals are known in this mix, it is difficult to predict the result. There is a fertilizer Triple 17 with NPK: Nitrogen 17%, Phosphorus 17% and Potassium 17%.  Assuming the grass seed with fertilizer had a somewhat balanced NPK and is not reapplied this season, then the bulbs may benefit from the application. Since the nitrogen was mixed with grass seed, a diluted effect might occur. The link below suggests that multiple applications of high nitrogen may cause excessive leaf growth, however granular bulb fertilizer in the fall could counteract high nitrogen.

Nitrogen fertilizer on lawns

Toronto Master Gardeners do not recommend any commercial products. However, you could contact the company who produced the high nitrogen grass seed and question the effect on embedded bulbs in the lawn. When researching high nitrogen fertilizer, Triple 17 fertilizer in particular is in link below. This fertilizer does aid in leaf growth and root growth, which may help the development of your bulbs. If the lawn is heavily watered during the season, root rot could occur, even without excess nitrogen.

How to Use Triple 17 fertilizer

If possible, hold off mowing the lawn until your current bulb leaves turn yellow. This will ensure good bulb development. Since the bulbs have been successful for a number of years, it is likely they will overcome the nitrogen boost and continue to emerge next spring. Below is a Toronto Master Gardening Guide which may suggest other bulbs for naturalizing to add to your lovely lawn display.

Bulbs for Naturalizing