Adjusting sub plot sizes


I have generated a heat map along side a tree with gridspec. The issue is that I want the tree with smaller dimensions and heat map should be in a square dimension, adjusting height ratios and width ration only helps reduce tree and the heat map dimensions increase.

Here is my code:

gs=gridspec.GridSpec(1, 2,height_ratios=[1,1,-2,2] ,width_ratios=[0.5,1,-2,2],hspace=0,wspace=0)


Phylo.draw(tree, axes=phyl_ax, do_show=False,show_confidence=False)


Hence I decided to use add_subplots instead:
from mpl_toolkits.axes_grid1 import make_axes_locatable,Size

from Bio import Phylo
    fig= plt.figure()
    divider1 = make_axes_locatable(phyl_ax)
    divider1.get_horizontal()[0] = Size.Fixed(5.0) # 10 inch

    divider1.get_vertical()[0] = Size.Fixed(10.0) # 4 inch
    Phylo.draw(tree, axes=phyl_ax, do_show=False,show_confidence=False)
    divider2 = make_axes_locatable(ht_ax)
    divider2.get_horizontal()[0] = Size.Fixed(10.0) # 5 inch

    divider2.get_vertical()[0] = Size.Fixed(10.0) # 5 inch
    divider = make_axes_locatable(ht_ax)
    cbax = divider.append_axes("right", size="5%", pad=0.10)

Note:The width of the subplots is what I am trying to make different and height should be the same.

With the above code the tree subplot is appearing in the background and heat map on top of it, rather than adjacent.

Could anyone help me out with this?