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Ask Dr. Phipps: Spindly Seedlings
Mar 31

Ask Dr. Phipps: Spindly Seedlings

By Phipps Master Gardeners

Q: I started some seedlings earlier this month, they have sprouted and are starting to grow very long, lanky stems. They don’t look good. Should I be worried? Did I do something wrong?

A: It sounds like a classic case of spindly seedlings!! This generally happens when seedlings are not receiving enough light. A south facing windowsill although sufficient for house plants, may not cut it for providing sunlight to vegetable seedlings which require 12 – 16 hours of light for maximum growth. For strong, healthy seedlings that will survive the windy, rainy conditions of Western Pennsylvanian yards, you will want to grow short, stout seedlings with thick stems and sturdy leaves. Along with providing enough water and a warm environment for your seedlings, having the right amount of light is important for healthy growth. 

Depending on how long your seedlings have been on the spindly side you may or may not be able to save them. If they have been growing for quite some time and have very long, thin stems with short leaves – it may be too late! It is probably better to just toss the plants into the compost bin and start over. If your seedlings have just recently started showing signs of spindly-ness – you may be able to save them, read on.

Providing enough light for growing veggies:

  • Artificial lights are the best option for veggies started inside; make sure the spectrum includes blue light.
  • Fluorescents are time-tested and reliable; two cool white tubes work fine for seedlings
  • LEDs will use less energy and are becoming more popular
  • Use a programmable timer and set it so that the lights are on for 12 – 16 hrs.
  • Position the lights a few inches above the seedlings (2 inches for fluorescent, more for LED) and move the lights up incrementally as the vegetable seedlings grow.

Read more about starting seeds and caring for your seedlings

Not sure when to start certain seeds or when to plant your seedlings outside? See planting calendars from our Homegrown program. 


Hello there at Phipps! I have planted a passion fruit and as it blossomed it was packed with caterpillars. Right now they’ve become beautiful butterflies. On the other hand as the flowers didn’t blossomed fully, there are no fruits. I was thinking of the year I spent in Pittsburgh for my PhD research and the wonderful times I spent at Phipps. There was a very special event which was the butterfly season. I was wondering what kind of trees you had in the outside garden which held them. Also I’d like to know what kind of plants I should have close enough to the passion fruit so the caterpillars would be attracted to this other plant for nourishment and stay away from the passion fruit. Can you give me some advice?

By Marina Conde on Apr 1, 2020

Hi Marina - thanks for your questions. Passion fruit can self pollinate or be pollinated by bees. So here are three possible reasons why the plant did not bear fruit. Plant is not fruit bearing, conditions for self pollination are less than ideal, or pollinators are not available.

In researching the butterflies, there are two butterflies that are hosted by the passion fruit. Agraulis vanillae and Dryas iulia. There are no other host plants listed for these butterflies. In fact, most people grow these vines to attract the butterflies, whose caterpillars eat the leaves. Can you confirm that the butterflies that you have are one of these two? or whether they are something else all together? You can send photos to .(JavaScript must be enabled to view this email address). Butterflies have specific host plants that they have adapted to eating and living with over many years. In order to recommend additional plants for you to use, we would need to know which specific butterflies you have. thanks!

By Phipps Master Gardeners on Apr 2, 2020