Arrows

Looking pretty good, only things are that hatching is a bit rushed, and that you can exaggerate more how they get bigger and bigger as they get closer to the viewer, more exponentially. Remember you can add overlaps with confident superimposed lines as well.

Leaves

On leaf of the bottom you should have been a bit bolder with the overlaps, don't be afraid to make them. They are good overall, but don't rush contours, take your time with them, and draw them completely.

Branches

Looking good too. You can overlap way sooner your next strokes to achieve a smoother transition.

Plants

First of all, the demos should constitute a maximum of 3 drawings of your submission, so you should have done a few more.

Demos themselves look good, though they have a few issues.

In your mushrooms, be careful with the allignment of the minor axis. It has to cut the ellipses in 2 identical symmetrical halves, so be sure you're aiming for it.

On the cactus, the little balls are texture, so they should be approached like it. Just like in lesson 2, don't outline forms, draw their cast shadows, and focus on them.

On the potato plant, you're overdoing the lineweight a bit. Only add lineweight to overlaps, and use only a single superimposed line. Be subtle with your lineweight.

Otherwise, completely avoid the use of hatching. When adding detail, do it just like in lesson 2. Draw only zones of black cast shadows, nothing else.

Noted a few things here, hopefully it'll help!