Nutrient issue or sunburn?

[ForerunnerBrewer]

I saw on another thread that you could sunburn your leaves simply by getting water droplets on them. I'm trying to figure out if my leaves have the same problem or if there is an issue with nutrition which Theredben suggested.

I can post another pict if you need something in greater detail.

These are my habits

It's been pretty sunny the past few weeks. I mixed the soil it is in with humus so it should have plenty of nutrients. I have some potting soil around the rhizomes to help with drainage and to make it easy for roots to go out. Once a week I give them a quarter cup of miracle grow which I pour mostly around and not directly under the plant as I have no idea how much is too much and I don't want to burn the roots.

I have been watering one or two cups twice per day per the forums but I am reducing it lately because the soil and mulch are doing well retaining enough water. I don't think I have flooded them before this.

I'm not too worried. However, my second Cascade that is right next to it hasn't grown more than an inch or two in height in the past 2 weeks and I'm wondering if there may be a connection.

High rez link: https://picasaweb.google.com/lh/photo/c04ew3zcs_pnQfa34kSwlA?feat=directlink

Thanks for the help!

 

[amb1935]

First off, I'm a total novice, but my experience with using fertilizer on infant plants has never been very good. It seems as if you have taken enough care of the soil that perhaps the fertilizer is throwing the chemical profile of the soil all out of whack. I haven't babies my first year growth at all, just made sure it's in good soil, and it's growing just fine.

 

[theredben]

On your lower leaves it looks like it could be fertilizer salt build-up. I would cut back on the miracle-gro to maybe once a week.

If you look at your hop leaf, you can see the veins radiating out to the edges. At the edge of the leaf at each vein there is something called a hydathode. This is basically a hole in the vein that pushes water out of the tip. When plants have excess water, particularly in the early morning, there will be a ring of drops of water around each leaf. When you have excess fertilizer in the soil those hydathodes push out a salty mix instead of pure water, and when the drops dry they turn into little spots of fertilizer salt. This is what burn the tips.

The fun part of plant nutrition is that yellowing of the leaf edges can also bee a potassium deficiency. Closer pics would help.